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 A153476 #4 Mar 30 2012 17:33:58 %S A153476 1,3,11,43,2091,34859,165931,537036843,576460752840460331, %T A153476 154742505487133287202850859,40564973949808827981181705422891, %U A153476 42535336430091257741749807110676449323 %N A153476 Sum of first n even superperfect numbers A061652, divided by 2. %C A153476 Also, sum of first n superperfect numbers A019279, divided by 2, if there are no odd superperfect numbers. %F A153476 a(n) = A153475(n)/2 [From _Max Alekseyev_, Jul 27 2009] %Y A153476 Cf. A153474, A153475. %K A153476 nonn %O A153476 1,2 %A A153476 _Omar E. Pol_, Dec 27 2008 %E A153476 More terms from _Max Alekseyev_, Jul 27 2009