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 A086123 #8 Jun 04 2024 01:26:40 %S A086123 2,6,10,12,46,126,148,180,618,928,3406,10948,13240,13872,16518,201358, %T A086123 396412,1888278,3300592 %N A086123 a(n) = A004061(n) - 1. %Y A086123 Cf. A004061. %K A086123 nonn,more %O A086123 1,1 %A A086123 _Labos Elemer_, Jul 23 2003 %E A086123 a(16)-a(19) added using the data at A004061 by _Amiram Eldar_, Jun 04 2024