A164740 (2^p-(p+2))/p as p runs through the primes.

0, 1, 5, 17, 185, 629, 7709, 27593, 364721, 18512789, 69273665, 3714566309, 53634713549, 204560302841, 2994414645857, 169947155749829, 9770521225481753, 37800705069076949, 2202596307308603177

Offset: 1

Author

Tanin (Mirza Sabbir Hossain Beg) (mirzasabbirhossainbeg(AT)yahoo.com), Aug 24 2009

Keywords

• nonn

Programs

Mathematica

f[n_] := Block[{p = Prime@n}, (2^p - p - 2)/p]; Array[f, 15]
Table[(2^p-p-2)/p,{p,Prime[Range[20]]}] (* Harvey P. Dale, Aug 15 2017 *)

Formula

a(n) = 2*A007663(n)-1. [T. D. Noe, Aug 24 2009]

Extensions

Edited by N. J. A. Sloane, Aug 24 2009

Extended and offset changed by T. D. Noe and Robert G. Wilson v, Aug 24 2009