OFFSET
0,2
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..1000
A. Burstein and T. Mansour, Words restricted by 3-letter ..., arXiv:math/0112281 [math.CO], 2001.
A. Burstein and T. Mansour, Words Restricted by 3-Letter Generalized Multipermutation Patterns, Annals. Combin., 7 (2003), 1-14.
Index entries for linear recurrences with constant coefficients, signature (3,0,-3,0,1).
MAPLE
seq(coeff(series(1/(1-3*x+3*x^3-x^5), x, n+1), x, n), n = 0 .. 30); # G. C. Greubel, Aug 07 2019
MATHEMATICA
CoefficientList[Series[x/((1-x^2)^3 -1+x), {x, 0, 30}], x] (* G. C. Greubel, Aug 07 2019 *)
LinearRecurrence[{3, 0, -3, 0, 1}, {1, 3, 9, 24, 63}, 30] (* Harvey P. Dale, Oct 29 2023 *)
PROG
(PARI) my(x='x+O('x^30)); Vec(x/((1-x^2)^3 -1+x)) \\ G. C. Greubel, Aug 07 2019
(Magma) R<x>:=PowerSeriesRing(Integers(), 30); Coefficients(R!( x/((1-x^2)^3 -1+x) )); // G. C. Greubel, Aug 07 2019
(Sage)
def A123880_list(prec):
P.<x> = PowerSeriesRing(ZZ, prec)
return P( x/((1-x^2)^3 -1+x) ).list()
A123888_list(30) # G. C. Greubel, Aug 07 2019
(GAP) a:=[1, 3, 9, 24, 63];; for n in [6..30] do a[n]:=3*a[n-1]-3*a[n-3]+ a[n-5]; od; a; # G. C. Greubel, Aug 07 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Nov 20 2006
STATUS
approved