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 A012833 #4 Feb 24 2012 12:51:09 %S A012833 1,-1,-3,-45,2457,-36825,12566037,-1732392389,313988548273, %T A012833 -92368244011185,30231378922437805,-12317648529216417629, %U A012833 6168347852710380187977,-3616136826996686827399305 %N A012833 sech(sec(x)*arcsinh(x))=1-1/2!*x^2-3/4!*x^4-45/6!*x^6+2457/8!*x^8... %K A012833 sign %O A012833 0,3 %A A012833 Patrick Demichel (patrick.demichel(AT)hp.com)