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 A009447 #11 Apr 01 2017 14:18:04 %S A009447 1,2,-24,-624,-7424,242560,23499776,1002251264,-2151563264, %T A009447 -5583112077312,-666018502836224,-39230927775531008, %U A009447 2301688982196453376,1098354240121833783296,184678513097428042776576 %N A009447 Expansion of sin(cosh(x)*x). %t A009447 Sin[ Cosh[ x ]*x ] (* Odd Part *) %K A009447 sign %O A009447 0,2 %A A009447 _R. H. Hardin_ %E A009447 Extended with signs by _Olivier Gérard_, Mar 15 1997