A372339 Decimal expansion of Sum_{k>=0} (-1)^k * (k+2) / ((k+1)*(2*k)!).

1, 3, 0, 3, 8, 4, 8, 8, 8, 7, 2, 2, 0, 2, 1, 2, 1, 6, 5, 5, 0, 7, 8, 1, 4, 4, 6, 5, 5, 8, 9, 5, 2, 7, 8, 1, 0, 4, 4, 2, 0, 5, 7, 3, 8, 3, 4, 5, 0, 5, 0, 8, 8, 1, 4, 3, 5, 5, 7, 9, 5, 1, 8, 6, 1, 2, 7, 1, 2, 1, 9, 9, 3, 1, 0, 5, 8, 9, 4, 6, 3, 1, 4, 5, 1, 1

Offset: 1

Author

Clark Kimberling, Apr 28 2024

Keywords

• nonn
• cons

Examples

			1.3038488872202121655078144655895278104420573...
		

Crossrefs

Cf. A049469, A049470, A372338.

Programs

Mathematica

s = Sum[(-1)^k (k + 2)/((k + 1) (2 k)!), {k, 0, Infinity}]
d = N[s, 100]
First[RealDigits[d]]

Formula

Equals -2 + 3*cos(1) + 2*sin(1).