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A110613
a(n+3) = 5*a(n+2) - 2*a(n+1) - 8*a(n), a(0) = 1, a(1) = 0, a(2) = 3.
3
1, 0, 3, 7, 29, 107, 421, 1659, 6597, 26299, 105029, 419771, 1678405, 6712251, 26846277, 107379643, 429507653, 1718008763, 6871991365, 27487878075, 109951337541, 439805000635, 1759219303493, 7036875815867, 28147500467269
OFFSET
0,3
COMMENTS
A Jacobsthal related sequence (A001045). This sequence was calculated using the same rules given for A108618; the "initial seed" is the floretion given in the program code, below.
FORMULA
G.f.: (1-5*x+5*x^2)/((4*x-1)*(2*x-1)*(x+1)).
Program "Superseeker" finds:
a(n) + a(n+1) = A007582(n) = A007581(n+1) - A007581(n).
a(n+2) - a(n) = A049775(n).
a(n) + 2*a(n+1) + a(n+2) = A087440(n+1).
MAPLE
seriestolist(series((1-5*x+5*x^2)/((4*x-1)*(2*x-1)*(x+1)), x=0, 25)); -or- Floretion Algebra Multiplication Program, FAMP Code: 2tessumseq[(.5'i - .5'k - .5i' + .5k' - .5'ij' - .5'ji' - .5'jk' - .5'kj')('i + j' + 'ij' + 'ji')] Sumtype is set to:sum[Y[15]] = sum(*) (from 3rd term, disregarding signs)
MATHEMATICA
LinearRecurrence[{5, -2, -8}, {1, 0, 3}, 50] (* G. C. Greubel, Sep 01 2017 *)
PROG
(PARI) x='x+O('x^50); Vec((1-5*x+5*x^2)/((4*x-1)*(2*x-1)*(x+1))) \\ G. C. Greubel, Sep 01 2017
KEYWORD
easy,nonn
AUTHOR
Creighton Dement, Jul 31 2005
STATUS
approved