This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A135629 #11 Sep 05 2025 01:56:01 %S A135629 7,29,497,8129,33550337,8589869057,137438691329,2305843008139952129, %T A135629 2658455991569831744654692615953842177, %U A135629 191561942608236107294793378084303638130997321548169217 %N A135629 Perfect numbers plus 1. %H A135629 G. C. Greubel, <a href="/A135629/b135629.txt">Table of n, a(n) for n = 1..15</a> %F A135629 a(n) = A000396(n) + 1. %t A135629 (# (# + 1))/2 & /@ Select[2^Range[100] - 1, PrimeQ] + 1 (* _G. C. Greubel_, Oct 24 2016, based on _Harvey P. Dale_ code from A000396 *) %Y A135629 Cf. A000396, A135627. %K A135629 easy,nonn,changed %O A135629 1,1 %A A135629 _Omar E. Pol_, Nov 27 2007