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

1,2

Links

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

Mathematica

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

Prog

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

Crossrefs

Cf. A000051, A000142, A069180.

Sequence in context: A181824 A326677 A330684 * A363122 A116882 A069519

Adjacent sequences: A070170 A070171 A070172 * A070174 A070175 A070176

Keyword

easy,nonn

Author

Benoit Cloitre, May 06 2002

Status

approved