OFFSET
1,1
COMMENTS
Partial sums of A133028. [From R. J. Mathar, Jan 21 2009]
FORMULA
a(n) = A092336(n)/2.
MATHEMATICA
Accumulate[(# (#+1))/2&/@Select[2^Range[90]-1, PrimeQ] ]/2 (* Harvey P. Dale, Sep 04 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Omar E. Pol, Dec 27 2008
EXTENSIONS
More terms from R. J. Mathar, Jan 21 2009
STATUS
approved