A070173 Numbers k such that k! and 2^k+1 are relatively prime.

1, 2, 4, 8, 12, 16, 24, 32, 40, 48, 56, 64, 72, 80, 88, 96, 104, 112, 128, 136, 144, 152, 160, 176, 184, 192, 200, 208, 224, 232, 248, 256, 272, 288, 304, 320, 352, 368, 384, 400, 416, 448, 464, 480, 496, 512, 544, 576, 592, 608, 640, 656, 688, 704, 752, 768

Offset: 1

Author

Benoit Cloitre, May 06 2002

Keywords

• easy
• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..3000

Crossrefs

Cf. A000051, A000142, A069180.

Programs

Mathematica

Select[Range[1000],CoprimeQ[#!,2^#+1]&]

PARI

for(n=1,1255,if(gcd(n!,2^n+1)==1,print1(n,",")))