A371942 Decimal expansion of Sum_{k>=0} (k+2)! / (2k+1)!.

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

Offset

1,1

Links

Table of n, a(n) for n=1..86.

Formula

Equals (1/16)*(22 + 25*e^(1/4)*sqrt(Pi)*erf(1/2)).

Equals 2* 1F1(3;3/2;1/4) . - R. J. Mathar, Aug 02 2024

Example

3.22592667646664554893879704543457089776442691317...

Mathematica

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

Crossrefs

Cf. A371947.

Sequence in context: A058608 A112196 A021035 * A259967 A007567 A093055

Adjacent sequences: A371939 A371940 A371941 * A371943 A371944 A371945

Keyword

nonn,cons

Author

Clark Kimberling, Apr 28 2024

Status

approved