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