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 A087240 #6 Sep 01 2018 17:43:58 %S A087240 25,87,240,774,1960,5378,15828,40420,110477,306255,823267,2219935, %T A087240 6035446,16314684,44245201,119849369,324308909,879921037,2385657333, %U A087240 6467079803,17541637367,47581552613,129104928784,350330765356,950772205549,2580621276899,7005302330033 %N A087240 First differences of A087235. %H A087240 Giovanni Resta, <a href="/A087240/b087240.txt">Table of n, a(n) for n = 2..49</a> %F A087240 a(n)=A087235(n+1)-A087235(n) %Y A087240 Cf. A038623-A038627, A057809, A087235-A087241. %K A087240 nonn %O A087240 2,1 %A A087240 _Labos Elemer_, Sep 04 2003 %E A087240 More terms from _Giovanni Resta_, Sep 01 2018