The On-Line Encyclopedia of Integer Sequences (OEIS)

A067315 revision #9

A067315

Numbers k such that binomial(k, floor(k/2)) is not divisible by k.

4, 6, 8, 10, 14, 16, 18, 20, 22, 24, 26, 28, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 86, 88, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 118, 120, 122, 124, 126, 128, 130, 134, 136, 138, 140

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

OFFSET

1,1

COMMENTS

All the terms are even. - Amiram Eldar, Aug 24 2024

LINKS

Table of n, a(n) for n=1..63.

Amiram Eldar, Table of n, a(n) for n = 1..10000

MATHEMATICA

Select[ Range[ 2, 150, 2 ], Mod[ Binomial[ #, #/2 ], # ]>0& ]

PROG

(PARI) is(k) = binomial(k, k\2) % k > 0; \\ Amiram Eldar, Aug 24 2024