OFFSET
0,2
COMMENTS
LINKS
Reinhard Zumkeller, Rows n = 0..20 of triangle, flattened
FORMULA
T(n,0) = A151821(n+1);
T(n,n-1) = A261256(n) for n > 0;
T(n,n) = A264959(n).
T(0,0) = A005117(1);
T(1,k) = A060687(k+1), k = 0..1;
T(2,k) = A195086(k+1), k = 0..2;
T(3,k) = A195087(k+1), k = 0..3;
T(4,k) = A195088(k+1), k = 0..4;
T(5,k) = A195089(k+1), k = 0..5;
T(6,k) = A195090(k+1), k = 0..6;
T(7,k) = A195091(k+1), k = 0..7;
T(8,k) = A195092(k+1), k = 0..8;
T(9,k) = A195093(k+1), k = 0..9;
T(10,k) = A195069(k+1), k = 0..10.
EXAMPLE
0: 1
1: 4 9
2: 8 24 27
3: 16 48 72 80
4: 32 96 144 160 216
5: 64 192 288 320 432 448
6: 128 384 576 640 864 896 1296
7: 256 768 1152 1280 1728 1792 2592 2816
8: 512 1536 2304 2560 3456 3584 5184 5632 6400
-- ------------------------------------------------------------
0: 1
1: 2^2 3^2
2: 2^3 2^3*3 3^3
3: 2^4 2^4*3 2^3*3^2 2^4*5
4: 2^5 2^5*3 2^4*3^2 2^5*5 2^3*3^3
5: 2^6 2^6*3 2^5*3^2 2^6*5 2^4*3^3 2^6*7
6: 2^7 2^7*3 2^6*3^2 2^7*5 2^5*3^3 2^7*7 2^4*3^4
7: 2^8 2^8*3 2^7*3^2 2^8*5 2^6*3^3 2^8*7 2^5*3^4 2^8*11
8: 2^9 2^9*3 2^8*3^2 2^9*5 2^7*3^3 2^9*7 2^6*3^4 2^9*11 2^8*5^2
MATHEMATICA
T[n_] := Reap[For[m = 1; k = 1, k <= n+1, If[PrimeOmega[m] - PrimeNu[m] == n, Sow[m]; k++]; m++]][[2, 1]];
Table[T[n], {n, 0, 10}] // Flatten (* Jean-François Alcover, Sep 17 2021 *)
PROG
(Haskell)
a257851 n k = a257851_tabl !! n !! k
a257851_row n = a257851_tabl !! n
a257851_tabl = map
(\x -> take (x + 1) $ filter ((== x) . a046660) [1..]) [0..]
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Reinhard Zumkeller, Nov 29 2015
STATUS
approved