A259320 a(n) = 2*n*A259319(n) - A259110(n)^2.

0, 256, 3584, 21504, 84480, 256256, 652288, 1462272, 2976768, 5617920, 9974272, 16839680, 27256320, 42561792, 64440320, 94978048, 136722432, 192745728, 266712576, 362951680, 486531584, 643340544, 840170496, 1084805120, 1386112000, 1754138880, 2200214016

Offset: 1

Author

N. J. A. Sloane, Jun 24 2015

Keywords

• nonn
• easy

Examples

			n=3: 3584 = 6*1414 - 70^2.
		

Links

• Colin Barker, Table of n, a(n) for n = 1..1000
• J. L. Bailey, Jr., A table to facilitate the fitting of certain logistic curves, Annals Math. Stat., 2 (1931), 355-359.
• J. L. Bailey, A table to facilitate the fitting of certain logistic curves, Annals Math. Stat., 2 (1931), 355-359. [Annotated scanned copy]
• Index entries for linear recurrences with constant coefficients, signature (7,-21,35,-35,21,-7,1).

Crossrefs

Cf. A259110, A259319.

Programs

Mathematica

LinearRecurrence[{7,-21,35,-35,21,-7,1},{0,256,3584,21504,84480,256256,652288},40] (* Harvey P. Dale, Mar 01 2020 *)

PARI

concat(0, Vec(-256*x^2*(x+1)*(x^2+6*x+1)/(x-1)^7 + O(x^100))) \\ Colin Barker, Jun 29 2015

Formula

a(n) = (64*(n^2-5*n^4+4*n^6))/45. - Colin Barker, Jun 29 2015

G.f.: -256*x^2*(x+1)*(x^2+6*x+1) / (x-1)^7. - Colin Barker, Jun 29 2015