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 A057928 #4 Jul 12 2022 19:53:22 %S A057928 0,-1,2,3,6,9,15,27,36,51,87,135,243,315,531,735,969,1707,2679,3831, %T A057928 6363,9663,14559,23091,33045,45999,77523,120471,177639,252717,405321, %U A057928 554037,795831,1335087,1819527,2491233,4183467,5920215,8051991,12530967,20132061 %N A057928 Position at which 2^n occurs in A057926, or -1 if it does not occur. %Y A057928 Cf. A057926, A057927. %K A057928 easy,sign %O A057928 0,3 %A A057928 Larry Reeves (larryr(AT)acm.org), Oct 03 2000 %E A057928 More terms from _Sean A. Irvine_, Jul 12 2022