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%I #7 Oct 25 2016 03:15:52
%S 7,29,497,8129,33550337,8589869057,137438691329,2305843008139952129,
%T 2658455991569831744654692615953842177,
%U 191561942608236107294793378084303638130997321548169217
%N Perfect numbers plus 1.
%H G. C. Greubel, <a href="/A135629/b135629.txt">Table of n, a(n) for n = 1..15</a>
%F a(n) = A000396(n) + 1.
%t (# (# + 1))/2 & /@ Select[2^Range[100] - 1, PrimeQ] + 1 (* G. C. Greubel, Oct 24 2016, based on Harvey P. Dale code from A000396 *)
%Y Cf. A000396, A135627.
%K easy,nonn
%O 1,1
%A _Omar E. Pol_, Nov 27 2007