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 A238261 #13 Aug 19 2021 07:19:50 %S A238261 4,9,1,0,8,1,4,9,6,4,5,6,8,2,5,5,8,9,8,7,5,1,5,3,4,8,0,5,2,4,0,3,5,2, %T A238261 1,9,7,8,9,8,7,0,5,2,8,1,7,6,7,8,4,7,1,7,6,1,3,9,4,1,1,2,0,2,2,5,6,4, %U A238261 1,7,8,7,7,8,7,9,9,4,7,9,7,2,9,5,1,8,1,9,7,4,1,5,3,5,5,4,4,6,1,4,2,5,0,5,3 %N A238261 Decimal expansion of a constant related to A187235. %H A238261 V. Kotesovec, <a href="https://oeis.org/wiki/User:Vaclav_Kotesovec">Non-attacking chess pieces</a>, 6ed, 2013, p.261. %F A238261 Equals lim n->infinity (A187235(n)/(n-1)!)^(1/n). %F A238261 Equals -(2*LambertW(-1,-exp(-1/2)/2))^2 / (1 + 2*LambertW(-1,-exp(-1/2)/2)). %e A238261 4.9108149645682558987515348... %t A238261 RealDigits[N[-(2*LambertW[-1,-1/2/Sqrt[E]])^2/(1+2*LambertW[-1,-1/2/Sqrt[E]]), 105]][[1]] %Y A238261 Cf. A187235, A238262, A002465, A129256, A342111, A330287. %K A238261 nonn,cons %O A238261 1,1 %A A238261 _Vaclav Kotesovec_, Feb 21 2014