OFFSET
2,2
LINKS
Nico Van Cleemput, Table of n, a(n) for n = 2..75
G. Brinkmann and N. Van Cleemput, Classification and generation of nanocones, Discrete Applied Mathematics, 159 (2011), 1528-1539.
FORMULA
Conjectured g.f.: x^2*(-x^11 + x^10 - x^9 + 4*x^8 + 5*x^7 + 10*x^6 + 9*x^5 + 11*x^4 + 4*x^3 + 7*x^2 + 2*x + 1) / ((x - 1)^6*(x + 1)^3*(x^2 + 1)*(x^2 + x + 1)). [D. S. McNeil, Oct 20 2011]
CROSSREFS
KEYWORD
nonn
AUTHOR
Nico Van Cleemput, Oct 20 2011
STATUS
approved