A047663 Row 6 of square array defined in A047662.

6, 42, 188, 644, 1826, 4494, 9912, 20040, 37758, 67122, 113652, 184652, 289562, 440342, 651888, 942480, 1334262, 1853754, 2532396, 3407124, 4520978, 5923742, 7672616, 9832920, 12478830, 15694146, 19573092, 24221148, 29755914, 36308006

Offset

1,1

Links

Muniru A Asiru, Table of n, a(n) for n = 1..10000

Index entries for linear recurrences with constant coefficients, signature (7, -21, 35, -35, 21, -7, 1).

Formula

a(n) = (n/45) * (2n^5 + 6n^4 + 35n^3 + 60n^2 + 98n + 69).

From Chai Wah Wu, Nov 01 2018: (Start)

a(n) = 7*a(n-1) - 21*a(n-2) + 35*a(n-3) - 35*a(n-4) + 21*a(n-5) - 7*a(n-6) + a(n-7) for n > 7.

G.f.: x*(-6*x^4 - 20*x^2 - 6)/(x - 1)^7. (End)

Maple

seq(coeff(series(x*(-6*x^4-20*x^2-6)/(x-1)^7, x, n+1), x, n), n = 1 .. 35); # Muniru A Asiru, Nov 21 2018

Mathematica

LinearRecurrence[{7, -21, 35, -35, 21, -7, 1}, {6, 42, 188, 644, 1826, 4494, 9912 }, 50] (* or *)
CoefficientList[Series[-((2 (3 + 10 x^2 + 3 x^4))/(-1 + x)^7), {x, 0, 50}], x] (* Stefano Spezia, Nov 01 2018 *)

Prog

(GAP) List([1..35], n->n/45*(2*n^5+6*n^4+35*n^3+60*n^2+98*n+69)); # Muniru A Asiru, Nov 21 2018

Crossrefs

Sequence in context: A253946 A359847 A062136 * A326744 A054642 A082139

Adjacent sequences: A047660 A047661 A047662 * A047664 A047665 A047666

Keyword

nonn

Author

N. J. A. Sloane

Status

approved