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A001722 Generalized Stirling numbers.
(Formerly M5061 N2191)
2

%I M5061 N2191 #22 Dec 24 2021 08:17:35

%S 1,18,251,3325,44524,617624,8969148,136954044,2201931576,37272482280,

%T 663644774880,12413008539360,243533741849280,5003753991174720,

%U 107497490419296000,2410964056571616000,56366432074677312000,1371711629236971456000,34699437370290760704000

%N Generalized Stirling numbers.

%C The asymptotic expansion of the higher order exponential integral E(x,m=3,n=5) ~ exp(-x)/x^3*(1 - 18/x + 251/x^2 - 3325/x^3 + 44524/x^4 - 617624/x^5 + ... ) leads to the sequence given above. See A163931 and A163932 for more information. - _Johannes W. Meijer_, Oct 20 2009

%D N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).

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

%H T. D. Noe, <a href="/A001722/b001722.txt">Table of n, a(n) for n = 0..100</a>

%H D. S. Mitrinovic and R. S. Mitrinovic, <a href="http://pefmath2.etf.rs/files/47/77.pdf">Tableaux d'une classe de nombres reliƩs aux nombres de Stirling</a>, Univ. Beograd. Publ. Elektrotehn. Fak. Ser. Mat. Fiz. No. 77 1962, 77 pp.

%F a(n) = Sum_{k=0..n} (-1)^(n+k)*binomial(k+2, 2)*5^k*Stirling1(n+2, k+2). - Borislav Crstici (bcrstici(AT)etv.utt.ro), Jan 26 2004

%F If we define f(n,i,a) = Sum_{k=0..n-i} binomial(n,k)*Stirling1(n-k,i)*Product_{j=0..k-1} (-a-j), then a(n-2) = |f(n,2,5)|, for n >= 2. - _Milan Janjic_, Dec 21 2008

%t Table[Sum[(-1)^(n + k)*Binomial[k + 2, 2]*5^k*StirlingS1[n + 2, k + 2], {k, 0, n}], {n, 0, 20}] (* _T. D. Noe_, Aug 10 2012 *)

%K nonn

%O 0,2

%A _N. J. A. Sloane_

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

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Last modified April 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)