A188444 Expansion of (1+x)*(1+x+x^2)*(1-x+x^2-4*x+x^4-x^5+x^6)/(1+x^4)^3.

1, 1, 1, -3, -9, -9, -6, 10, 25, 25, 15, -21, -49, -49, -28, 36, 81, 81, 45, -55, -121, -121, -66, 78, 169, 169, 91, -105, -225, -225, -120, 136, 289, 289, 153, -171, -361, -361, -190, 210, 441, 441, 231, -253, -529, -529, -276, 300, 625, 625, 325

Offset

0,4

Comments

a(n+1) is the Hankel transform of A166300(n+3) (diagonal sums of the triangle A100754).

Links

Table of n, a(n) for n=0..50.

Index entries for linear recurrences with constant coefficients, signature (0,0,0,-3,0,0,0,-3,0,0,0,-1).

Formula

G.f.: (1+x+x^2-3*x^3-6*x^4-6*x^5-3*x^6+x^7+x^8+x^9)/(1+x^4)^3.

a(n) = -3*a(n-4) - 3*a(n-8) - a(n-12). - Wesley Ivan Hurt, Mar 17 2023

Crossrefs

Sequence in context: A268107 A306963 A084762 * A201409 A111120 A100401

Adjacent sequences: A188441 A188442 A188443 * A188445 A188446 A188447

Keyword

sign,easy

Author

Paul Barry, Mar 31 2011

Status

approved