A110212 a(n+3) = 6*a(n) - 5*a(n+2), a(0) = -1, a(1) = 5, a(2) = -25.

-1, 5, -25, 119, -565, 2675, -12661, 59915, -283525, 1341659, -6348805, 30042875, -142164421, 672729275, -3183389125, 15063959099, -71283419845, 337316764475, -1596200067781, 7553299819835, -35742598512325, 169135792154939, -800359161855685, 3787340218204475

Offset

0,2

Comments

Superseeker finds: a(n+1) - a(n) = ((-1)^n)*A030192(n+1) (Scaled Chebyshev U-polynomial evaluated at sqrt(6)/2).

Floretion Algebra Multiplication Program, FAMP Code: 2basejsumseq[A*B] with A = + 'i + 'ii' + 'ij' + 'ik' and B = + .5'i - .5'j + .5'k + .5i' + .5j' - .5k' - .5'ij' - .5'ik' + .5'ji' + .5'ki' Sumtype is set to: sum[(Y[0], Y[1], Y[2]),mod(3).

Links

Table of n, a(n) for n=0..23.

Formula

G.f.: 1/((x-1)*(6*x^2+6*x+1)).

Maple

S := taylor(1/((x-1)*(6*x^2+6*x+1)), x, 25):
seq(coeff(S, x, n), n=0..20);

Crossrefs

Cf. A030192, A110210, A110211, A110213.

Sequence in context: A238808 A383993 A034274 * A344097 A268940 A269636

Adjacent sequences: A110209 A110210 A110211 * A110213 A110214 A110215

Keyword

easy,sign

Author

Creighton Dement, Jul 16 2005

Status

approved