OFFSET
0,3
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
FORMULA
G.f. (for offset 1): (1+3*x-2*x^2-sqrt(1-6*x+x^2))/(2*(3+x-3*x^2+x^3)).
Conjecture: 3*(n+1)*a(n) +(10-17*n)*a(n-1) -6*(n+1)*a(n-2) +10*(2*n-1)*a(n-3) +9*(1-n)*a(n-4) +(n-2)*a(n-5) =0. - _R. J. Mathar_, Nov 17 2011
a(n) ~ sqrt(3*sqrt(2)-4) * (3+2*sqrt(2))^(n+2) / (36 * sqrt(Pi) * n^(3/2)). - _Vaclav Kotesovec_, Feb 01 2014
MATHEMATICA
Rest[CoefficientList[Series[(1+3*x-2*x^2-Sqrt[1-6*x+x^2])/(2*(3+x-3*x^2+x^3)), {x, 0, 20}], x]] (* _Vaclav Kotesovec_, Feb 01 2014 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
_Paul Barry_, Mar 01 2011
EXTENSIONS
More terms from _Vincenzo Librandi_, Feb 14 2014
STATUS
approved