A109781 Expansion of (-1+x+2*x^2-6*x^3+x^4+x^5) / ((x-1)*(x^2-x+1)*(x^2-2*x-1)*(x+1)^2).

-1, 3, -6, 11, -27, 60, -141, 337, -808, 1943, -4687, 11306, -27287, 65869, -159012, 383877, -926753, 2237366, -5401467, 13040283, -31482014, 76004289, -183490573, 442985412, -1069461373, 2581908135, -6233277618, 15048463343, -36330204279, 87708871872, -211747947993

Offset

0,2

Comments

Floretion Algebra Multiplication Program, FAMP Code: 1tessumseq[A*C] with A = + .5'k + .5k' + .5'ii' + .5'jj' and C = - .5'j + .5'k - .5j' + .5k' - 'ii' - .5'ij' - .5'ik' - .5'ji' - .5'ki'; sumtype: sum[Y[15]] = sum[ * ]

Links

Colin Barker, Table of n, a(n) for n = 0..1000

Index entries for linear recurrences with constant coefficients, signature (-2,2,1,-3,2,2,-1).

Formula

a(n) = -2*a(n-1) + 2*a(n-2) + a(n-3) - 3*a(n-4) + 2*a(n-5) + 2*a(n-6) - a(n-7) for n>6. - Colin Barker, May 14 2019

Prog

(PARI) Vec(-(1 - x - 2*x^2 + 6*x^3 - x^4 - x^5) / ((1 - x)*(1 + x)^2*(1 + 2*x - x^2)*(1 - x + x^2)) + O(x^30)) \\ Colin Barker, May 14 2019

Crossrefs

Sequence in context: A331536 A365294 A221182 * A360888 A101958 A153982

Adjacent sequences: A109778 A109779 A109780 * A109782 A109783 A109784

Keyword

easy,sign

Author

Creighton Dement, Aug 13 2005

Status

approved