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 A138827 #18 Mar 15 2020 05:16:08 %S A138827 2,4,7,10,19,25,19,37,82,115,142,172,745,856,1603,2980,3079,4240,5812, %T A138827 5842,13165,13480,15136,27052,29455,31339,60112,116386,149239,179821, %U A138827 291511,1025683,1164760,1703224,1891861,4038604,4091767,9440575,18241120,28450837,32576617 %N A138827 Sum of digits of n-th even superperfect number A061652(n). %C A138827 Also, sum of digits of n-th superperfect number A019279(n), if there are no odd superperfect numbers. %F A138827 a(n) = A007953(A061652(n)). - _Michel Marcus_, Mar 15 2020 %Y A138827 Cf. A007953, A061652. %Y A138827 Cf. A007605, A019279, A066538. %K A138827 nonn,base %O A138827 1,1 %A A138827 _Omar E. Pol_, Apr 01 2008 %E A138827 a(10)-a(33) from _R. J. Mathar_, May 22 2008 %E A138827 More terms from _Jinyuan Wang_, Mar 15 2020