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A154420 Maximal coefficient of MacMahon polynomial (cf. A060187) p(x,n)=2^n*(1 - x)^(n + 1)* LerchPhi[x, -n, 1/2]; that is, a(n) = Max(coefficients(p(x,n)). 2
1, 1, 6, 23, 230, 1682, 23548, 259723, 4675014, 69413294, 1527092468, 28588019814, 743288515164, 16818059163492, 504541774904760, 13397724585164019, 455522635895576646, 13892023109165902550, 527896878148304296900 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,3

COMMENTS

Since the center is the maximum in the Pascal, Eulerian and MacMahon triangles, a(n)=MacMahon[n,Floor[n/2]]

LINKS

Vaclav Kotesovec, Table of n, a(n) for n = 0..300

Peter Luschny, Generalized Eulerian polynomials.

FORMULA

a(n) ~ sqrt(3) * 2^(n+1) * n^n / exp(n). - Vaclav Kotesovec, Oct 28 2021

MAPLE

gf := proc(n, k) local f; f := (x, t) -> x*exp(t*x/k)/(1-x*exp(t*x));

series(f(x, t), t, n+2); ((1-x)/x)^(n+1)*k^n*n!*coeff(%, t, n):

collect(simplify(%), x) end:

seq(coeff(gf(n, 1), x, iquo(n, 2)), n=0..18); # Middle Eulerian numbers, A006551.

seq(coeff(gf(n, 2), x, iquo(n, 2)), n=0..18); # Middle midpoint Eulerian numbers.

# Peter Luschny, May 02 2013

MATHEMATICA

p[x_, n_] = 2^n*(1 - x)^(n + 1)* LerchPhi[x, -n, 1/2];

Table[Max[CoefficientList[FullSimplify[ExpandAll[p[x, n]]], x]], {n, 0, 30}]

CROSSREFS

Cf. A060187, A006551.

Sequence in context: A219168 A013260 A013266 * A255305 A339628 A304271

Adjacent sequences:  A154417 A154418 A154419 * A154421 A154422 A154423

KEYWORD

nonn

AUTHOR

Roger L. Bagula, Jan 09 2009

EXTENSIONS

Edited by N. J. A. Sloane, Jan 15 2009

STATUS

approved

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Last modified May 25 19:19 EDT 2022. Contains 354071 sequences. (Running on oeis4.)