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 A256831 #8 Apr 10 2015 15:57:57 %S A256831 1,1,4,1,9,8,2,5,6,9,6,6,7,7,9,1,2,0,6,0,2,8,0,4,3,3,3,8,3,6,7,8,6,0, %T A256831 1,5,0,8,6,4,7,3,0,4,8,2,4,0,8,5,4,0,7,9,1,5,5,6,2,5,4,3,5,2,4,4,9,8, %U A256831 4,3,7,8,5,4,8,0,6,2,0,8,6,0,7,8,2,5,0,6,3,7,0,6,0,9,2,5,3,3,4,7,8,1,6,3,6 %N A256831 Decimal expansion of Pell factorial constant. %F A256831 Equals limit n->infinity A256832(n) / ((1+sqrt(2))^(n*(n+1)/2) / 2^(3*n/2)). %e A256831 1.141982569667791206028043338367860150864730482408540791556... %t A256831 RealDigits[N[QPochhammer[2*Sqrt[2]-3], 105]][[1]] %Y A256831 Cf. A000129, A099929, A256832. %Y A256831 Cf. A062073, A218490, A253924. %K A256831 nonn,cons %O A256831 1,3 %A A256831 _Vaclav Kotesovec_, Apr 10 2015