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A097192
Main diagonal of triangle A097190, in which the n-th row polynomial R_n(y) is formed from the initial (n+1) terms of g.f. A097191(y)^(n+1), where R_n(1/3) = 9^n for all n>=0.
4
1, 24, 612, 15912, 417690, 11027016, 292215924, 7764594552, 206732329947, 5512862131920, 147193418922264, 3934078651195056, 105236603919467748, 2817102935690367408, 75458114348849127000, 2022277464549156603600
OFFSET
0,2
LINKS
FORMULA
G.f.: A(x) = 1/(1-27*x)^(8/9).
a(n) = (n+1)*A097193(n).
Conjecture: n*a(n) +3*(1-9*n)*a(n-1) = 0. - R. J. Mathar, Nov 16 2012
MAPLE
seq(coeff(series(1/(1-27*x)^(8/9), x, n+1), x, n), n = 0 ..20); # G. C. Greubel, Sep 17 2019
MATHEMATICA
CoefficientList[Series[(1-27*x)^(-8/9), {x, 0, 20}], x] (* G. C. Greubel, Sep 17 2019 *)
PROG
(PARI) a(n)=polcoeff(1/(1-27*x+x*O(x^n))^(8/9), n, x)
(Magma) R<x>:=PowerSeriesRing(Rationals(), 20); Coefficients(R!( 1/(1-27*x)^(8/9) )); // G. C. Greubel, Sep 17 2019
(Sage)
def A097192_list(prec):
P.<x> = PowerSeriesRing(QQ, prec)
return P(1/(1-27*x)^(8/9)).list()
A097192_list(20) # G. C. Greubel, Sep 17 2019
CROSSREFS
KEYWORD
nonn
AUTHOR
Paul D. Hanna, Aug 03 2004
STATUS
approved