OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..1000
B. K. Miceli, J, Remmel, Minimal Overlapping Embeddings and Exact Matches in Words, PU. M. A., Vol. 23 (2012), No. 3, pp. 291-315.
Index entries for linear recurrences with constant coefficients, signature (2,0,0,0,0,0,-1,1,1).
FORMULA
G.f.: (1+x^7+x^8)/(1-2*x+x^7-x^8-x^9). - Alois P. Heinz, Jan 08 2014
MAPLE
a:= n-> coeff(series(-(x^8+x^7+1)/(x^9+x^8-x^7+2*x-1), x, n+1), x, n):
seq(a(n), n=0..60); # Alois P. Heinz, Jan 08 2014
MATHEMATICA
a[n_ /; n<=8]:= 2^n; a[n_]:= a[n] =2*a[n-1] -a[n-7] +a[n-8] +a[n-9]; Table[a[n], {n, 0, 33}] (* Jean-François Alcover, Mar 18 2014 *)
PROG
(PARI) my(x='x+O('x^60)); Vec((1+x^7+x^8)/(1-2*x+x^7-x^8-x^9)) \\ G. C. Greubel, Sep 14 2019
(Magma) I:=[1, 2, 4, 8, 16, 32, 64, 128, 256]; [n le 9 select I[n] else 2*Self(n-1) - Self(n-7) + Self(n-8) + Self(n-9): n in [1..60]]; // G. C. Greubel, Sep 14 2019
(Sage)
def A234590_list(prec):
P.<x> = PowerSeriesRing(ZZ, prec)
return P((1+x^7+x^8)/(1-2*x+x^7-x^8-x^9)).list()
A234590_list(60) # G. C. Greubel, Sep 14 2019
(GAP) a:=[1, 2, 4, 8, 16, 32, 64, 128, 256];; for n in [10..60] do a[n]:=2*a[n-1] -a[n-7]+a[n-8]+a[n-9]; od; a; # G. C. Greubel, Sep 14 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
N. J. A. Sloane, Jan 01 2014
EXTENSIONS
a(17)-a(33) from Alois P. Heinz, Jan 08 2014
STATUS
approved