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 A338167 #26 Mar 21 2021 12:04:21
%S A338167 5,1,5,7,5,4,0,7,8,6,6,1,5,5,0,6,1,1,2,3,8,3,8,0,8,8,8,3,8,4,6,5,6,9,
%T A338167 2,4,2,4,2,9,7,5,9,6,7,5,5,6,7,4,2,3,6,0,2,2,6,1,6,8,7,0,8,7,8,7,8,4,
%U A338167 4,0,5,4,5,9,2,8,4,8,1,9,6,0,3,6,6,3,0
%N A338167 Decimal expansion of Sum_{n>=1} 1/(2n)^(2n-1).
%C A338167 Is the sum of the inverse of even numbers raised to the odd numbers.
%F A338167 Equals Sum_{n>=1} 1/A085535(n).
%e A338167 0.51575407866155061123838088838465692424297596755674236022...
%o A338167 (PARI) suminf(n=1, (2*n)^(-2*n+1))
%Y A338167 Cf. A085535, A338168.
%K A338167 nonn,cons
%O A338167 0,1
%A A338167 _Mario Cortés_, Oct 14 2020
%E A338167 More terms from _Jon E. Schoenfield_, Mar 21 2021