A081766 Numbers k such that k^2+1 divides C(2k,k).

0, 1, 3, 8, 13, 17, 30, 46, 47, 68, 73, 75, 93, 98, 105, 112, 122, 144, 155, 172, 183, 189, 192, 203, 217, 233, 237, 242, 254, 266, 268, 269, 278, 286, 294, 348, 380, 401, 403, 411, 423, 437, 439, 443, 456, 463, 476, 483, 489, 494, 498, 511, 520, 526, 540, 563

Offset

1,3

Links

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

Mathematica

Select[Range[0, 600], Divisible[Binomial[2*#, #], #^2 + 1] &] (* Amiram Eldar, May 08 2022 *)

Crossrefs

Cf. A000984, A002522.

Sequence in context: A022807 A292655 A187093 * A152676 A197062 A010064

Adjacent sequences: A081763 A081764 A081765 * A081767 A081768 A081769

Keyword

easy,nonn

Author

Benoit Cloitre, Apr 09 2003

Extensions

a(1) = 0 inserted by Amiram Eldar, May 08 2022

Status

approved