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Search: a137492 -id:a137492
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Numbers with 37 divisors.
+10
19
68719476736, 150094635296999121, 14551915228366851806640625, 2651730845859653471779023381601, 30912680532870672635673352936887453361, 12646218552730347184269489080961456410641
OFFSET
1,1
COMMENTS
36th powers of primes. The n-th number with p divisors is equal to the n-th prime raised to power p-1, where p is prime.
FORMULA
a(n) = A000040(n)^(37-1) = A000040(n)^36.
MAPLE
A139572 := proc(n) ithprime(n)^36 ; end proc: seq(A139572(n), n=1..10) ; # R. J. Mathar, Feb 05 2010
MATHEMATICA
Prime[Range[10]]^36 (* Vladimir Joseph Stephan Orlovsky, May 05 2011 *)
PROG
(PARI) a(n)=prime(n)^36 \\ Charles R Greathouse IV, Jun 19 2016
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, May 07 2008
EXTENSIONS
More terms from R. J. Mathar, Feb 05 2010
STATUS
approved
Numbers with 43 divisors.
+10
18
4398046511104, 109418989131512359209, 227373675443232059478759765625, 311973482284542371301330321821976049, 54763699237492901685126120802225273763666521, 61040881526285814362156628321386486455989674569
OFFSET
1,1
COMMENTS
42nd powers of primes. The n-th number with p divisors is equal to the n-th prime raised to power p-1, where p is prime.
FORMULA
a(n)=A000040(n)^(43-1)=A000040(n)^42.
MATHEMATICA
Prime[Range[9]]^42 (* Vladimir Joseph Stephan Orlovsky, May 05 2011 *)
PROG
(PARI) a(n)=prime(n)^42 \\ Charles R Greathouse IV, Jun 19 2016
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, May 09 2008
EXTENSIONS
More terms from R. J. Mathar, May 11 2008
STATUS
approved
Numbers with 41 divisors.
+10
17
1099511627776, 12157665459056928801, 9094947017729282379150390625, 6366805760909027985741435139224001, 452592555681759518058893560348969204658401
OFFSET
1,1
COMMENTS
40th powers of primes. The n-th number with p divisors is equal to the n-th prime raised to power p-1, where p is prime.
FORMULA
a(n)=A000040(n)^(41-1)=A000040(n)^40.
MATHEMATICA
Prime[Range[9]]^40 (* Vladimir Joseph Stephan Orlovsky, May 05 2011 *)
PROG
(PARI) a(n)=prime(n)^40 \\ Charles R Greathouse IV, Jun 19 2016
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, May 07 2008
EXTENSIONS
More terms from Jon E. Schoenfield, May 18 2010
STATUS
approved
Numbers with 47 divisors.
+10
17
70368744177664, 8862938119652501095929, 142108547152020037174224853515625, 749048330965186233494494102694564493649, 801795320536133573571931534665380233173841533961
OFFSET
1,1
COMMENTS
46th powers of primes. The n-th number with p divisors is equal to the n-th prime raised to power p-1, where p is prime.
FORMULA
a(n)=A000040(n)^(47-1)=A000040(n)^46.
MATHEMATICA
Prime[Range[9]]^46 (* Vladimir Joseph Stephan Orlovsky, May 06 2011 *)
PROG
(PARI) a(n)=prime(n)^46 \\ Charles R Greathouse IV, Jun 19 2016
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, May 09 2008
EXTENSIONS
More terms from R. J. Mathar, May 11 2008
STATUS
approved
Numbers with 53 divisors.
+10
12
4503599627370496, 6461081889226673298932241, 2220446049250313080847263336181640625, 88124787089723195184393736687912818113311201, 1420429319844313329730664601483335671261683881745483121, 8415003868347247618489696679505181495471801448798649088081
OFFSET
1,1
COMMENTS
52nd powers of primes.
The n-th number with p divisors is equal to the n-th prime raised to power p-1, where p is prime.
FORMULA
a(n) = A000040(n)^(53-1) = A000040(n)^52.
MATHEMATICA
Prime[Range[9]]^52 (* Vladimir Joseph Stephan Orlovsky, May 06 2011 *)
PROG
(PARI) a(n)=prime(n)^52 \\ Charles R Greathouse IV, Jun 19 2016
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, Oct 16 2010
STATUS
approved
Numbers with 59 divisors.
+10
11
288230376151711744, 4710128697246244834921603689, 34694469519536141888238489627838134765625, 10367793076318844190248738727596255138212949486449
OFFSET
1,1
COMMENTS
Also, 58th powers of primes.
The n-th number with p divisors is equal to the n-th prime raised to power p-1, where p is prime.
FORMULA
a(n) = A000040(n)^(59-1) = A000040(n)^58.
A000005(a(n)) = 59.
PROG
(PARI) a(n)=prime(n)^58 \\ Charles R Greathouse IV, Jul 31 2011
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, Jul 31 2011
STATUS
approved
Numbers with 61 divisors.
+10
11
1152921504606846976, 42391158275216203514294433201, 867361737988403547205962240695953369140625, 508021860739623365322188197652216501772434524836001
OFFSET
1,1
COMMENTS
Also, 60th powers of primes.
The n-th number with p divisors is equal to the n-th prime raised to power p-1, where p is prime.
FORMULA
a(n) = A000040(n)^(61-1) = A000040(n)^60.
A000005(a(n)) = 61.
PROG
(PARI) a(n)=prime(n)^60
KEYWORD
nonn
AUTHOR
Omar E. Pol, Jul 31 2011
STATUS
approved
Numbers with 30 divisors.
+10
8
720, 1008, 1200, 1584, 1620, 1872, 2268, 2352, 2448, 2592, 2736, 2800, 3312, 3564, 3888, 3920, 4050, 4176, 4212, 4400, 4464, 4608, 5200, 5328, 5508, 5808, 5904, 6156, 6192, 6768, 6800, 7452, 7500, 7600, 7632, 7938, 8112, 8496, 8624, 8784, 9200, 9396
OFFSET
1,1
COMMENTS
Maple implementation: see A030513.
Numbers of the form p^29 (subset of A122970), p*q^2*r^4 (A179669), p^4*q^5 (A179702), p^2*q^9 (like 4608) or p*q^14, where p, q and r are distinct primes. - R. J. Mathar, Mar 01 2010
FORMULA
A000005(a(n))=30.
MATHEMATICA
Select[Range[10000], DivisorSigma[0, #]==30&] (* Harvey P. Dale, Feb 18 2011 *)
PROG
(PARI) is(n)=numdiv(n)==30 \\ Charles R Greathouse IV, Jun 19 2016
(PARI) list(lim)=
{
my(f=(v, s)->concat(v, listsig(lim, s, 1)));
Set(fold(f, [[], [29], [5, 4], [9, 2], [14, 1], [4, 2, 1]]));
}
listsig(lim, sig, coprime)=
{
my(e=sig[1]);
if(#sig<2,
if(#sig==0 || sig[1]==0, return(if(lim<1, [], [1])));
my(P=primes([2, sqrtnint(lim\1, e)]));
if(coprime==1, return(if(e>1, apply(p->p^e, P), P)));
P=select(p->gcd(p, coprime)==1, P);
if(e>1, P=apply(p->p^e, P));
return(P);
);
my(v=List(), ss=sig[2..#sig], t=leastOfSig(ss));
forprime(p=2, sqrtnint(lim\t, e),
if(coprime%p,
my(u=listsig(lim\p^e, ss, coprime*p));
for(i=1, #u, listput(v, p^e*u[i]));
)
);
Vec(v);
} \\ Charles R Greathouse IV, Nov 18 2021
CROSSREFS
Cf. A137492 (29 divs), A139571 (31 divs).
KEYWORD
nonn
AUTHOR
R. J. Mathar, Apr 22 2008
STATUS
approved
Numbers with 101 divisors.
+10
8
1267650600228229401496703205376, 515377520732011331036461129765621272702107522001, 7888609052210118054117285652827862296732064351090230047702789306640625, 3234476509624757991344647769100216810857203198904625400933895331391691459636928060001
OFFSET
1,1
COMMENTS
Also, 100th powers of primes.
The n-th number with p divisors is equal to the n-th prime raised to power p-1, where p is prime.
FORMULA
a(n) = A000040(n)^(101-1) = A000040(n)^100.
A000005(a(n)) = 101.
EXAMPLE
a(1) = 2^100, a(2) = 3^100, a(3) = 5^100, a(4) = 7^100.
PROG
(PARI) a(n)=prime(n)^100 \\ Charles R Greathouse IV, Jun 19 2016
KEYWORD
nonn,easy
AUTHOR
Omar E. Pol, Aug 28 2015
STATUS
approved
Square array T(n,k) read by antidiagonal upwards in which row n lists the n-th powers of primes, hence column k lists the powers of the k-th prime, n >= 0, k >= 1.
+10
8
1, 2, 1, 4, 3, 1, 8, 9, 5, 1, 16, 27, 25, 7, 1, 32, 81, 125, 49, 11, 1, 64, 243, 625, 343, 121, 13, 1, 128, 729, 3125, 2401, 1331, 169, 17, 1, 256, 2187, 15625, 16807, 14641, 2197, 289, 19, 1, 512, 6561, 78125, 117649, 161051, 28561, 4913, 361, 23, 1, 1024, 19683, 390625, 823543, 1771561, 371293
OFFSET
0,2
COMMENTS
If n = p - 1 where p is prime, then row n lists the numbers with p divisors.
The partial sums of column k give the column k of A319076.
FORMULA
T(n,k) = A000040(k)^n, n >= 0, k >= 1.
EXAMPLE
The corner of the square array is as follows:
A000012 1, 1, 1, 1, 1, 1, 1, ...
A000040 2, 3, 5, 7, 11, 13, 17, ...
A001248 4, 9, 25, 49, 121, 169, 289, ...
A030078 8, 27, 125, 343, 1331, 2197, 4913, ...
A030514 16, 81, 625, 2401, 14641, 28561, 83521, ...
A050997 32, 243, 3125, 16807, 161051, 371293, 1419857, ...
A030516 64, 729, 15625, 117649, 1771561, 4826809, 24137569, ...
A092759 128, 2187, 78125, 823543, 19487171, 62748517, 410338673, ...
A179645 256, 6561, 390625, 5764801, 214358881, 815730721, 6975757441, ...
...
PROG
(PARI) T(n, k) = prime(k)^n;
CROSSREFS
Other rows n: A030635 (n=16), A030637 (n=18), A137486 (n=22), A137492 (n=28), A139571 (n=30), A139572 (n=36), A139573 (n=40), A139574 (n=42), A139575 (n=46), A173533 (n=52), A183062 (n=58), A183085 (n=60), A261700 (n=100).
Main diagonal gives A093360.
Second diagonal gives A062457.
Third diagonal gives A197987.
Removing the 1's we have A182944/ A182945.
KEYWORD
nonn,tabl,easy
AUTHOR
Omar E. Pol, Sep 09 2018
STATUS
approved

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