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 A058756 #3 Mar 30 2012 16:48:57 %S A058756 1,-2,-2,-2,-6,-10,-34,-82,-254,-730,-2238,-6826,-21370,-67122, %T A058756 -213654,-684258,-2208694,-7169298,-23402738,-76748130,-252790518, %U A058756 -835816658,-2773236614,-9230776706,-30814377058,-103139338858,-346067984622,-1163810570178 %N A058756 G.f. is (1-S)/(1+S), where S = g.f. for A000084. %Y A058756 Cf. A036655, A000137. %K A058756 sign %O A058756 0,2 %A A058756 _N. J. A. Sloane_, Jan 01 2001