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A172397 a(n) = a(n-1) + a(n-2) - a(n-3) - a(n-8), starting 1,1,2,2,3,3,4,4. 1
1, 1, 2, 2, 3, 3, 4, 4, 4, 3, 1, -2, -7, -13, -22, -32, -45, -58, -72, -83, -90, -88, -73, -39, 21, 113, 245, 420, 642, 905, 1200, 1502, 1776, 1965, 1994, 1763, 1150, 14, -1799, -4437, -8026, -12629, -18212, -24578, -31311, -37691, -42625, -44568, -41476 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,3
LINKS
FORMULA
G.f.: 1/(1 - x - x^2 + x^3 + x^8).
MATHEMATICA
f[-6]=0; f[-5]=0; f[-4]=0; f[-3]=0; f[-2]=0; f[-1]=0; f[0]=1; f[1]=1;
f[n_]:= f[n] =f[n-1]+f[n-2]-f[n-3]-f[n-8]; Table[f[n], {n, 0, 50}]
LinearRecurrence[{1, 1, -1, 0, 0, 0, 0, -1}, {1, 1, 2, 2, 3, 3, 4, 4}, 50] (* _Harvey P. Dale_, Nov 20 2012 *)
PROG
(PARI) my(x='x+O('x^50)); Vec(1/(1-x-x^2+x^3+x^8)) \\ _G. C. Greubel_, Mar 01 2019
(Magma) R<x>:=PowerSeriesRing(Integers(), 50); Coefficients(R!( 1/(1-x-x^2+x^3+x^8) )); // _G. C. Greubel_, Mar 01 2019
(Sage) (1/(1-x-x^2+x^3+x^8)).series(x, 50).coefficients(x, sparse=False) # _G. C. Greubel_, Mar 01 2019
(GAP) a:=[1, 1, 2, 2, 3, 3, 4, 4];; for n in [9..50] do a[n]:=a[n-1]+a[n-2]-a[n-3]-a[n-8]; od; a; # _G. C. Greubel_, Mar 01 2019
CROSSREFS
Cf. A023438.
Sequence in context: A079730 A035486 A282347 * A237815 A238701 A238134
KEYWORD
sign,easy
AUTHOR
_Roger L. Bagula_, Nov 20 2010
EXTENSIONS
More terms from _Harvey P. Dale_, Nov 20 2012
STATUS
approved

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Last modified March 3 15:08 EST 2024. Contains 370512 sequences. (Running on oeis4.)