OFFSET
1,8
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
Allan Fordy and Andrew Hone, Discrete integrable systems and Poisson algebras from cluster maps, arXiv:1207.6072 [nlin.SI], 2012. See Example 3.7.
FORMULA
Empirical g.f.: -x*(x^7+x^6-x^4+x^3+2*x^2+x-1) / ((x-1)*(x^2+x+1)*(x^4-x^3-2*x^2-x+1)*(x^6+x^3+1)). - Colin Barker, Jul 22 2013
MATHEMATICA
Join[{-1}, RecurrenceTable[{d[n + 6] + d[n] == Max[2*d[n + 5] + 2*d[n + 1], 2*d[n + 4] + 4*d[n + 3] + 2*d[n + 2]], d[2] == 0, d[3] == 0, d[4] == 0, d[5] == 0, d[6] == 0, d[7] == 1}, d, {n, 2, 50}]] (* G. C. Greubel, Aug 10 2018 *)
PROG
(PARI) a=vector(99); a[1]= -1; a[2]=a[3]=a[4]=a[5]=a[6]=0; for(n=7, #a, a[n]=2*max(a[n-1]+a[n-5], a[n-2]+2*a[n-3]+a[n-4])-a[n-6]); a; \\ Michel Marcus, Feb 08 2013
CROSSREFS
KEYWORD
sign
AUTHOR
N. J. A. Sloane, Dec 23 2012
EXTENSIONS
More terms from Michel Marcus, Feb 08 2013
Definition corrected by N. J. A. Sloane, Jan 11 2024 at the suggestion of Helmut Ruhland.
STATUS
approved