0,4

From Johannes W. Meijer, Oct 20 2009: (Start)

The asymptotic expansion of the higher order exponential integral E(x,m=3,n=6) ~ exp(-x)/x^3*(1 - 21/x + 335/x^2 - 5000/x^3 + 74524/x^4 - 1139292/x^5 + ...) leads to the sequence given above. See A163931 and A163932 for more information.

(End)

Mitrinovic, D. S. and Mitrinovic, R. S. see reference given for triangle A051338.

a(n) = A051338(n, 2)*(-1)^n; e.g.f.: (log(1-x))^2/(2*(1-x)^6).

If we define f(n,i,a)=sum(binomial(n,k)*stirling1(n-k,i)*product(-a-j,j=0..k-1),k=0..n-i), then a(n) = |f(n,2,6)|, for n>=1. - Milan Janjic, Dec 21 2008

Cf. A001725 (m=0), A051524 (m=1) unsigned columns.

Sequence in context: A016191 A297336 A095905 * A107396 A036224 A113895

Adjacent sequences: A051522 A051523 A051524 * A051526 A051527 A051528

easy,nonn

approved