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 A138867 #8 Mar 14 2020 05:56:56 %S A138867 2,4,16,64,40,65,26,10,11,30,81,85,34,26,52,73,22,12,95,14,23,17,14, %T A138867 21,22,20,42,26,26,25,37,87,64,20,40,31,63,21,46,62,14,61,15,62,10,84, %U A138867 15 %N A138867 First two digits of n-th even superperfect number A061652(n). %C A138867 Also, first two digits of n-th superperfect number A019279(n), if there are no odd superperfect numbers. %Y A138867 Cf. A019279, A061652, A138862, A138868, A138869, A138873. %K A138867 nonn,base,more %O A138867 1,1 %A A138867 _Omar E. Pol_, Apr 02 2008 %E A138867 a(12)-a(31) from _R. J. Mathar_, Feb 05 2010 %E A138867 a(32)-a(47) from _Jinyuan Wang_, Mar 14 2020