A001724 Generalized Stirling numbers.

1, 35, 835, 17360, 342769, 6687009, 131590430, 2642422750, 54509190076, 1159615530788, 25497032420496, 580087776122400, 13662528306823824, 333132304121991504, 8407011584355624288, 219490450157530821024, 5925108461354500651776, 165275526944869750483200

Offset: 0

Author

N. J. A. Sloane

Keywords

• nonn

Comments

The asymptotic expansion of the higher order exponential integral E(x,m=5,n=5) ~ exp(-x)/x^5*(1 - 35/x + 835/x^2 - 17360/x^3 + 342769/x^4 - ...) leads to the sequence given above. See A163931 for E(x,m,n) information and A163932 for a Maple procedure for the asymptotic expansion. - Johannes W. Meijer, Oct 20 2009

References

• N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
• N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

• T. D. Noe, Table of n, a(n) for n = 0..100
• D. S. Mitrinovic, M. S. Mitrinovic, Tableaux d'une classe de nombres relies aux nombres de Stirling, Univ. Beograd. Pubi. Elektrotehn. Fak. Ser. Mat. Fiz. 77 (1962).
• Karol A. Penson and Karol Zyczkowski, Product of Ginibre matrices : Fuss-Catalan and Raney distribution, arXiv version, arXiv:1103.3453 [math-ph], 2011.

Programs

Mathematica

Table[Sum[(-1)^(n + k)*Binomial[k + 4, 4]*5^k*StirlingS1[n + 4, k + 4], {k, 0, n}], {n, 0, 20}] (* T. D. Noe, Aug 10 2012 *)

PARI

a(n) = sum(k=0, n, (-1)^(n+k)*binomial(k+4, 4)*5^k*stirling(n+4, k+4, 1)) \\ Michel Marcus, Jan 20 2016

Formula

a(n) = sum((-1)^(n+k)*binomial(k+4, 4)*5^k*stirling1(n+4, k+4), k=0..n). - Borislav Crstici (bcrstici(AT)etv.utt.ro), Jan 26 2004

E.g.f.: (6-156*log(1-x)+753*log(1-x)^2-1066*log(1-x)^3+420*log(1-x)^4)/(6*(1-x)^9). - Vladeta Jovovic, Mar 01 2004

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-4) = |f(n,4,5)|, for n>=4. - Milan Janjic, Dec 21 2008

Extensions

More terms from Borislav Crstici (bcrstici(AT)etv.utt.ro), Jan 26 2004