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 A056919 #7 Jul 02 2025 16:02:00 %S A056919 0,1,1,0,-2,-2,4,10,-6,-46,-16,214,310,-974,-3144,3674,28826,-566, %T A056919 -260000,-254906,2345094,4894154,-20901880,-74737574,176084986, %U A056919 1072935874,-1216168944,-15164335306,1862029910,214162724194,186232275544,-3026208587366,-6005924996070,42413412401786 %N A056919 Numerators of continued fraction for left factorial. %F A056919 a(0)=0; a(1)=1; a(n) = a(n-1) - floor(n/2)*a(n-2). %K A056919 sign,frac,easy %O A056919 0,5 %A A056919 _Aleksandar Petojevic_, Sep 05 2000 %E A056919 More terms from _James Sellers_, Sep 06 2000