A163929 Denominators of the higher order exponential integral constants alpha(2,n).

1, 1, 16, 1296, 20736, 12960000, 4320000, 10372320000, 165957120000, 40327580160000, 40327580160000, 590436101122560000, 590436101122560000, 16863445484161436160000, 2409063640594490880000, 2409063640594490880000

Offset

1,3

Comments

See A163927 for information about the constants alpha(k,n).

Links

Table of n, a(n) for n=1..16.

Formula

alpha(k,n) = (1/k)*Sum_{i=0..k-1} Sum_{p=0..n-1} p^(-2*(k-i))*alpha(i, n) with alpha(0,n) = 1. For this sequence, k = 2 and n >= 1.

Example

alpha(k=2, n=1) = 0, alpha(k=2, 2) = 1, alpha(k=2, 3) = 21/16, and alpha(k=2, 4) = 1897/1296.

Crossrefs

Cf. A163928 (numerators).

Sequence in context: A173544 A248619 A334585 * A072914 A007480 A369169

Adjacent sequences: A163926 A163927 A163928 * A163930 A163931 A163932

Keyword

nonn,frac

Author

Johannes W. Meijer & Nico Baken, Aug 13 2009, Aug 17 2009

Status

approved