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 A371934 #15 Jul 03 2024 08:01:04
%S A371934 7,6,3,5,4,6,5,8,1,3,5,2,0,7,2,4,4,8,1,0,6,8,7,7,8,5,8,1,4,6,5,5,1,2,
%T A371934 0,6,7,0,9,7,4,6,9,6,2,8,3,2,5,8,6,5,8,6,6,8,5,6,9,7,9,3,0,7,4,6,0,2,
%U A371934 1,5,9,8,3,3,1,4,2,2,8,6,6,9,3,3,1,8
%N A371934 Decimal expansion of Sum_{k>=0} (-1)^k / ((k+1)*(2*k)!).
%F A371934 Equals 2*(A143623 - 1).
%e A371934 0.7635465813520724481068778581465512067097...
%p A371934 hypergeom([1], [1/2, 2], -1/4) ; evalf(%) ; # _R. J. Mathar_, Jul 03 2024
%t A371934 s = N[Sum[(-1)^k/((k + 1) (2 k)!), {k, 0, Infinity}], 120]
%t A371934 First[RealDigits[s]]
%Y A371934 Cf. A143623, A334397.
%K A371934 nonn,cons
%O A371934 0,1
%A A371934 _Clark Kimberling_, Apr 24 2024