A072974 - OEIS

A072974

Numbers n such that (50n-6) divides C(3n,n)*2^n.

15, 21, 27, 30, 51, 56, 57, 63, 69, 75, 84, 87, 89, 90, 99, 100, 102, 108, 111, 113, 123, 124, 129, 130, 132, 135, 138, 139, 153, 156, 159, 165, 166, 171, 183, 192, 195, 197, 201, 207, 210, 215, 216, 220, 221, 232, 246, 251, 258, 263, 264, 267, 273, 279, 283

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OFFSET

1,1

COMMENTS

Previous name was "Numbers n such that C(3n,n)*2^n/(50n-6) is an integer".

LINKS

Table of n, a(n) for n=1..55.

PROG

(PARI) isok(n) = ((binomial(3*n, n)*2^n) % (50*n-6)) == 0; \\ Michel Marcus, Nov 28 2013

CROSSREFS

Sequence in context: A138594 A131651 A134642 * A226025 A082686 A102030

Adjacent sequences: A072971 A072972 A072973 * A072975 A072976 A072977