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A006199 Bessel polynomial {y_n}'(-1).
(Formerly M3082)
4
0, 1, -3, 21, -185, 2010, -25914, 386407, -6539679, 123823305, -2593076255, 59505341676, -1484818160748, 40025880386401, -1159156815431055, 35891098374564105, -1183172853341759129, 41372997479943753582, -1529550505546305534414, 59608871544962952539335 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,3
COMMENTS
Absolute values give partitions into pairs.
REFERENCES
G. Kreweras and Y. Poupard, Sur les partitions en paires d'un ensemble fini totalement ordonné, Publications de l'Institut de Statistique de l'Université de Paris, 23 (1978), 57-74.
J. Riordan, Combinatorial Identities, Wiley, 1968, p. 77.
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
LINKS
FORMULA
a(n) = A000806(n) + (n-1) * A000806(n-1). - Sean A. Irvine, Jan 23 2017
From G. C. Greubel, Aug 14 2017: (Start)
a(n) = 2*n*(1/2)_{n} * (-2)^(n-1) * hyergeometric1f1(1-n; -2*n; -2), where (a)_{n} is the Pochhammer symbol.
E.g.f.: (1+2*x)^(-3/2)*( (1+2*x)^(3/2) - x*(1+2*x)^(1/2) - x -1) * exp(sqrt(1+2*x) - 1), for offset 0. (End)
G.f.: (x/(1-x)^3)*hypergeometric2f0(2,3/2; - ; -2*x/(1-x)^2), for offset 0. - G. C. Greubel, Aug 16 2017
MATHEMATICA
Join[{0}, Table[2*n*Pochhammer[1/2, n]*(-2)^(n - 1)* Hypergeometric1F1[1 - n, -2*n, -2], {n, 1, 50}]] (* G. C. Greubel, Aug 14 2017 *)
PROG
(PARI) for(n=0, 50, print1(sum(k=0, n-1, ((n+k)!/(k!*(n-k)!))*(-1/2)^k), ", ")) \\ G. C. Greubel, Aug 14 2017
CROSSREFS
Sequence in context: A054879 A333090 A131763 * A083063 A012163 A012055
KEYWORD
sign
AUTHOR
STATUS
approved

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Last modified August 29 03:06 EDT 2024. Contains 375510 sequences. (Running on oeis4.)