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A164740
(2^p-(p+2))/p as p runs through the primes.
2
0, 1, 5, 17, 185, 629, 7709, 27593, 364721, 18512789, 69273665, 3714566309, 53634713549, 204560302841, 2994414645857, 169947155749829, 9770521225481753, 37800705069076949, 2202596307308603177
OFFSET
1,3
FORMULA
a(n) = 2*A007663(n)-1. [T. D. Noe, Aug 24 2009]
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 *)
CROSSREFS
Sequence in context: A097490 A355277 A309178 * A053678 A090645 A206328
KEYWORD
nonn
AUTHOR
Tanin (Mirza Sabbir Hossain Beg) (mirzasabbirhossainbeg(AT)yahoo.com), 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
STATUS
approved