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
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