A192374 Coefficient of x in the reduction of the polynomial p(n,x) defined at A162517 and below in Comments.

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

Offset: 1

Author

Clark Kimberling, Jun 29 2011

Keywords

• nonn

Comments

The polynomials p(n,x) is defined by ((x+d)^n-(x-d)^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.

Examples

			(See A192373.)
		

Crossrefs

Cf. A192232, A192373, A192375.

Programs

Mathematica

(See A192373.)

Formula

Empirical G.f.: 2*x^2/(9*x^4+6*x^3-10*x^2-2*x+1). [Colin Barker, Nov 23 2012]