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 A261114 #41 Sep 20 2022 07:54:02
%S A261114 2,2,5,4,6,3,2,6,4,3,7,5,1,6,0,7,5,1,7,4,6,6,0,9,1,7,6,1,9,4,2,3,6,2,
%T A261114 4,8,7,3,6,0,2,8,6,2,4,2,7,9,1,0,8,1,6,9,7,0,1,4,3,0,0,8,6,5,2,0,9,2,
%U A261114 7,1,9,4,4,7,4,0,9,3,0,9,8,8,9,0,5,9,5
%N A261114 Decimal expansion of Sum_{n>=0} 1/((n!)^n).
%H A261114 <a href="/A261114/b261114.txt">Table of n, a(n) for n = 1..440</a>
%e A261114 2.2546326437516075174660917619423624873602862427910816970143008652092...
%t A261114 RealDigits[N[Sum[1/((n!)^n), {n, 0, Infinity}], 120]] // First (* _Michael De Vlieger_, Sep 22 2015 *)
%o A261114 (PARI) suminf(k=0, 1/k!^k) \\ _Michel Marcus_, Sep 20 2022
%Y A261114 Sum of 1/A036740(n).
%K A261114 cons,easy,nonn
%O A261114 1,1
%A A261114 _Daniel Suteu_, Sep 20 2015