OFFSET
1,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 1..1000
Svenja Huntemann, Neil A. McKay, Counting Domineering Positions, arXiv:1909.12419 [math.CO], 2019.
Index entries for linear recurrences with constant coefficients, signature (4,4,-4,-1).
FORMULA
a(n) = Sum_{k=1..n} Fibonacci(k)^3*a(n-k), with a(0)=1. - Vladeta Jovovic, Apr 23 2003
G.f.: x*(1-2*x-x^2)/(1-4*x-4*x^2+4*x^3+x^4). - Vaclav Kotesovec, Nov 27 2012
MAPLE
seq(coeff(series(x^4/((1+2*x)*(2*x^3+x^2-2*x+1)), x, n+1), x, n), n = 0..40); # G. C. Greubel, Dec 29 2019
MATHEMATICA
CoefficientList[Series[(1-2*x-x^2)/(1-4*x-4*x^2+4*x^3+x^4), {x, 0, 40}], x] (* Vincenzo Librandi, May 05 2013 *)
LinearRecurrence[{4, 4, -4, -1}, {1, 2, 11, 48}, 40] (* Harvey P. Dale, May 28 2014 *)
PROG
(PARI) my(x='x+O('x^66)); Vec(x*(1-2*x-x^2)/(1-4*x-4*x^2+4*x^3+x^4)) \\ Joerg Arndt, May 06 2013
(Magma) R<x>:=PowerSeriesRing(Integers(), 40); Coefficients(R!( x*(1-2*x-x^2)/(1-4*x-4*x^2+4*x^3+x^4) )); // G. C. Greubel, Dec 29 2019
(Sage)
def A054894_list(prec):
P.<x> = PowerSeriesRing(ZZ, prec)
return P( x*(1-2*x-x^2)/(1-4*x-4*x^2+4*x^3+x^4) ).list()
a=A054894_list(40); a[1:] # G. C. Greubel, Dec 29 2019
(GAP) a:=[1, 2, 11, 48];; for n in [5..40] do a[n]:=4*(a[n-1]+a[n-2]-a[n-3]) -a[n-4]; od; a; # G. C. Greubel, Dec 29 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Barry Cipra, Jul 04 2000
STATUS
approved