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 A372367 #6 May 18 2024 15:09:29
%S A372367 3,6,6,4,0,4,0,2,4,7,8,3,0,5,7,5,9,9,6,7,3,6,2,3,3,2,4,1,8,3,9,4,7,8,
%T A372367 5,8,9,7,0,3,5,7,0,9,2,2,2,9,9,8,5,7,7,4,4,6,2,2,7,6,0,2,3,2,4,3,4,7,
%U A372367 4,7,4,7,7,5,9,7,2,4,6,0,8,4,9,3,8,9
%N A372367 Decimal expansion of Sum_{k>=0} (-1)^k*(k+1) / (k^2+1).
%e A372367 0.3664040247830575996736233241839478589703570922299...
%t A372367 s = Sum[ (-1)^k (k + 1)/(k^2 + 1), {k, 0, Infinity}]
%t A372367 d = Chop[N[s, 100]]
%t A372367 First[RealDigits[d]]
%Y A372367 Cf. A372387.
%K A372367 nonn,cons
%O A372367 0,1
%A A372367 _Clark Kimberling_, May 12 2024