A372367 Decimal expansion of Sum_{k>=0} (-1)^k*(k+1) / (k^2+1).
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, 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, 4, 7, 4, 7, 7, 5, 9, 7, 2, 4, 6, 0, 8, 4, 9, 3, 8, 9
Offset: 0
Examples
0.3664040247830575996736233241839478589703570922299...
Crossrefs
Cf. A372387.
Programs
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Mathematica
s = Sum[ (-1)^k (k + 1)/(k^2 + 1), {k, 0, Infinity}] d = Chop[N[s, 100]] First[RealDigits[d]]