

A192374


Coefficient of x in the reduction of the polynomial p(n,x) defined at A162517 and below in Comments.


3



0, 2, 4, 28, 84, 406, 1448, 6200, 23688, 97034, 380716, 1533844, 6079452, 24339742, 96844496, 386805104, 1541301648, 6150529682, 24521644756, 97819530508, 390080615652, 1555871900710, 6204937972088, 24747735482792, 98698893741336
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OFFSET

1,2


COMMENTS

The polynomials p(n,x) is defined by ((x+d)^n(xd)^n)/(2d), where d=sqrt(x+4). A192374=2*A192375. For an introduction to reductions of polynomials by substitutions such as x^2>x+1, see A192232.


LINKS



FORMULA

Empirical G.f.: 2*x^2/(9*x^4+6*x^310*x^22*x+1). [Colin Barker, Nov 23 2012]


EXAMPLE



MATHEMATICA



CROSSREFS



KEYWORD

nonn


AUTHOR



STATUS

approved



