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 A138787 #18 Oct 24 2024 09:26:12 %S A138787 1,3,11,43,187,857,4144,20812,107822,572918,3108512,17164308,96199106, %T A138787 546137465,3135381256,18177991951 %N A138787 First differences of A007878. %F A138787 a(n) = A007878(n+1)-A007878(n). %Y A138787 Cf. A007878, A138788. %K A138787 nonn,more %O A138787 1,2 %A A138787 _Artur Jasinski_, Mar 30 2008 %E A138787 a(9)-a(11) from _Vaclav Kotesovec_, Mar 29 2019 %E A138787 a(12)-a(13) from _Seiichi Manyama_, Nov 08 2023 %E A138787 a(14)-a(16) from the data at A007878 added by _Amiram Eldar_, Oct 24 2024