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Revision History for A088312 (Underlined text is an addition; strikethrough text is a deletion.)

Showing entries 1-10 | older changes
A088312 Number of sets of lists (cf. A000262) with even number of lists.
(history; published version)
#36 by Peter Luschny at Wed Dec 14 06:30:08 EST 2022
STATUS

editing

approved

#35 by Peter Luschny at Wed Dec 14 06:26:52 EST 2022
FORMULA

a(n) = (1/2)*(n-1)*n!*hypergeom([1 - n/2, 3/2 - n/2], [3/2, 3/2, 2], 1/4) for n >= 1. - Peter Luschny, Dec 14 2022

MAPLE

A088312 := n -> ifelse(n=0, 1, (1/2)*(n - 1)*n!*hypergeom([1 - n/2, 3/2 - n/2], [3/2, 3/2, 2], 1/4)): seq(simplify(A088312(n)), n = 0..21); # Peter Luschny, Dec 14 2022

STATUS

approved

editing

#34 by Peter Luschny at Wed Dec 14 06:12:13 EST 2022
STATUS

reviewed

approved

#33 by Michel Marcus at Wed Dec 14 00:31:14 EST 2022
STATUS

proposed

reviewed

#32 by G. C. Greubel at Wed Dec 14 00:01:15 EST 2022
STATUS

editing

proposed

#31 by G. C. Greubel at Wed Dec 14 00:01:01 EST 2022
COMMENTS

a(n) = (1/2)*(A000262(n) + (-1)^n*A111884(n)).

FORMULA

a(n) = (1/2)*(A000262(n) + (-1)^n*A111884(n)). - Peter Bala, Mar 27 2022

MATHEMATICA

Rest[Rest[With[{m=30}, CoefficientList[Series[Cosh[x/(1-x)], {x, , 0, 20, m}], x] * Range[0, 20]!]] (* _, m]!] (* _Vaclav Kotesovec_, Jul 04 2015 *)

Table[Sum[n!/(2*k)! Binomial[n - 1, 2*k - 1], {k, 0, Floor[n/2]}], {n, 0, 1230}] (* Emanuele Munarini, Sep 03 2017 *)

PROG

(Magma) R<x>:=PowerSeriesRing(Rationals(), 30); Coefficients(R!(Laplace( Cosh(x/(1-x)) ))); // G. C. Greubel, Dec 13 2022

(SageMath)

def A088312_list(prec):

P.<x> = PowerSeriesRing(QQ, prec)

return P( cosh(x/(1-x)) ).egf_to_ogf().list()

A088312_list(40) # G. C. Greubel, Dec 13 2022

CROSSREFS

Cf. A000262, A001710, A027187, A024429, A024430, A001710, A088313, A111884.

STATUS

approved

editing

#30 by Michel Marcus at Tue Mar 29 03:40:04 EDT 2022
STATUS

reviewed

approved

#29 by Joerg Arndt at Tue Mar 29 03:32:54 EDT 2022
STATUS

proposed

reviewed

#28 by Michel Marcus at Mon Mar 28 00:46:54 EDT 2022
STATUS

editing

proposed

#27 by Michel Marcus at Mon Mar 28 00:46:50 EDT 2022
LINKS

N. Heninger, E. M. Rains and N. J. A. Sloane, <a href="httphttps://arXivarxiv.org/abs/math.NT/0509316">On the Integrality of n-th Roots of Generating Functions</a>, arXiv:math/0509316 [math.NT], 2005-2006; J. Combinatorial Theory, Series A, 113 (2006), 1732-1745.

STATUS

proposed

editing

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Last modified August 30 02:56 EDT 2024. Contains 375521 sequences. (Running on oeis4.)