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

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