OFFSET
0,5
REFERENCES
Y. Ito, I. Nakamura, Hilbert schemes and simple singularities, New trends in algebraic geometry (Warwick, 1996), 151-233, Cambridge University Press, 1999.
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (1, 0, -1, 2, -1, 0, 1, -1).
FORMULA
G.f.: (1-x^9)/((1-x)(1-x^4)(1-x^6)).
a(0)=1, a(1)=1, a(2)=1, a(3)=1, a(4)=2, a(5)=2, a(6)=3, a(7)=3, a(n)= a(n-1)- a(n-3)+2*a(n-4)-a(n-5)+a(n-7)-a(n-8). [Harvey P. Dale, May 09 2012]
MATHEMATICA
CoefficientList[Series[(1-x^9)/((1-x)(1-x^4)(1-x^6)), {x, 0, 30}], x] (* or *) LinearRecurrence[{1, 0, -1, 2, -1, 0, 1, -1}, {1, 1, 1, 1, 2, 2, 3, 3}, 31] (* Harvey P. Dale, May 09 2012 *)
PROG
(PARI) Vec((1-x^9)/((1-x)*(1-x^4)*(1-x^6)) + O(x^80)) \\ Michel Marcus, Aug 19 2015
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Boddington, Oct 23 2003
EXTENSIONS
More terms from Michel Marcus, Aug 19 2015
STATUS
approved