A222392 Decimal expansion of Sum_{n>=1} 1/Gamma(n/2).

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

Offset: 1

Author

Bruno Berselli, Mar 19 2013

Keywords

• nonn
• cons

Examples

			5.57316966431003975325790404977558240053838531356466534303248120641829030...
		

References

• Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 43, equation 43:5:12 at page 415.

Links

• Vincenzo Librandi, Table of n, a(n) for n = 1..5000

Crossrefs

Cf. A222391.

Cf. A001113, (Sum_{n>=1} 1/Gamma(n)).

Programs

Mathematica

RealDigits[(1 + Erf[1]) E + 1/Sqrt[Pi], 10, 90][[1]]

Formula

Equals (1+erf(1))*e+1/sqrt(Pi), where erf is the error function (see A099286).