A362266 - OEIS

A362266

Triangle read by rows: T(n,k) = LCM({p_j-1 : j=1..n})/(p_k-1) for prime p.

1, 2, 1, 4, 2, 1, 12, 6, 3, 2, 60, 30, 15, 10, 6, 60, 30, 15, 10, 6, 5, 240, 120, 60, 40, 24, 20, 15, 720, 360, 180, 120, 72, 60, 45, 40, 7920, 3960, 1980, 1320, 792, 660, 495, 440, 360, 55440, 27720, 13860, 9240, 5544, 4620, 3465, 3080, 2520, 1980

(list; table; graph; refs; listen; history; text; internal format)

OFFSET

1,2

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..11325 (rows n = 1..150, flattened)

FORMULA

T(n,1) = A058254(n), T(n,k) = A058254(n)/A006093(k).

EXAMPLE

First 10 rows of the triangle:

1: 1

2: 2 1

3: 4 2 1

4: 12 6 3 2

5: 60 30 15 10 6

6: 60 30 15 10 6 5

7: 240 120 60 40 24 20 15

8: 720 360 180 120 72 60 45 40

9: 7920 3960 1980 1320 792 660 495 440 360

10: 55440 27720 13860 9240 5544 4620 3465 3080 2520 1980

...

MATHEMATICA

nn = 10; Array[Set[s[#], Prime[#] - 1] &, nn + 1]; Flatten@ Table[Table[#/s[k], {k, n}] &[LCM @@ Array[s, n]], {n, nn}]

PROG

(PARI) row(n) = my(L=lcm(apply(p->p-1, primes(n)))); vector(n, k, L/(prime(k)-1)); \\ Michel Marcus, Jul 15 2023

CROSSREFS

Cf. A006093, A058254.

Sequence in context: A127124 A127136 A239101 * A145983 A245025 A257495

Adjacent sequences: A362263 A362264 A362265 * A362267 A362268 A362269

KEYWORD

nonn,tabl

AUTHOR

Michael De Vlieger, Jul 10 2023

STATUS

approved