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 A262309 #5 Oct 04 2015 20:05:10 %S A262309 1,-1,-5,11,-125,1054,-209,-15625,14035,-130525,1899830,-134905, %T A262309 -25499225,-64447293,-133867445,6309965146,-11762712973,-29646853725, %U A262309 -160561408097,-1495301415045,24032249395590,-42497223256645,-176218120143125,271151209742715,-6483574667232425 %N A262309 Bisection of A008705. %Y A262309 Cf. A008705, A262308. %K A262309 sign %O A262309 0,3 %A A262309 _N. J. A. Sloane_, Oct 04 2015