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 A153475 #6 Mar 02 2023 12:56:52 %S A153475 2,6,22,86,4182,69718,331862,1074073686,1152921505680920662, %T A153475 309485010974266574405701718,81129947899617655962363410845782, %U A153475 85070672860182515483499614221352898646 %N A153475 Sum of the first n even superperfect numbers (A061652). %C A153475 Also, sum of first n superperfect numbers A019279, if there are no odd superperfect numbers. %F A153475 a(n) = A061652(1) + A061652(2) + ... + A061652(n). - _Max Alekseyev_, Jul 27 2009 %Y A153475 Cf. A092336, A019279, A061652, A153474, A153476. %K A153475 nonn %O A153475 1,1 %A A153475 _Omar E. Pol_, Dec 27 2008 %E A153475 More terms from _Max Alekseyev_, Jul 27 2009