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 A156175 #2 Mar 30 2012 16:51:15 %S A156175 1,1681,67637281,15442193173681,11735529528739490881, %T A156175 22427641105413135505628881,90592214447886493688036507587681, %U A156175 687051872949101429716075902637226327281,8977220765593827294384825469501847565263767681,189320918307961834904462117789058282666933576006788881 %N A156175 A bisection of A002439. %K A156175 nonn %O A156175 0,2 %A A156175 _N. J. A. Sloane_, Nov 07 2009