A128891 Decimal expansion of e^Pi*(1+erf(sqrt(Pi))).

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

Offset

2,1

Comments

This constant and the constant of A128892 are connected by the equation Sum_{n>=0} S_n - 2*Pi*Sum{n>=0} V_n = 2, where S_n and V_n are respectively the area and volume of an n-dimensional sphere of unit radius. - Philippe A.J.G. Chevalier, Dec 17 2015

References

Jerome Spanier and Keith B. Oldham, "Atlas of Functions", Hemisphere Publishing Corp., 1987, chapter 41, page 400.

Links

G. C. Greubel, Table of n, a(n) for n = 2..5002

Formula

Sum_{n>=0} Pi^(n/2)/Gamma(n/2+1), where the summand is the volume of a ball in n dimensions. - Jean-François Alcover, Apr 14 2015

Example

45.9993260893828553662740531827001975528647961835874132957770302131...

Mathematica

RealDigits[E^Pi*(1 + Erf[Sqrt[Pi]]), 10, 111][[1]] (* Robert G. Wilson v, Apr 22 2007 *)

Prog

(MATLAB) exp(pi)*(1+erf(sqrt(pi))) \\ Altug Alkan, Nov 11 2015
(PARI) exp(Pi)*(2-erfc(sqrt(Pi))) \\ Michel Marcus, Nov 11 2015

Crossrefs

Cf. A128892.

Sequence in context: A178610 A197268 A218505 * A172180 A193959 A093667

Adjacent sequences: A128888 A128889 A128890 * A128892 A128893 A128894

Keyword

nonn,cons

Author

Philippe Deléham, Apr 20 2007

Extensions

More terms from Robert G. Wilson v, Apr 22 2007

Status

approved