OFFSET
1,1
FORMULA
G.f.: (1 + 3*x + x^2 - sqrt(x^4 + 2*x^3 + 7*x^2 - 6*x + 1))/(2*x). - Vaclav Kotesovec, Mar 02 2014
Recurrence: (n+1)*a(n) = 3*(2*n-1)*a(n-1) - 7*(n-2)*a(n-2) - (2*n-7)*a(n-3) - (n-5)*a(n-4). - Vaclav Kotesovec, Mar 02 2014
MATHEMATICA
CoefficientList[Series[(1+3*x+x^2-Sqrt[x^4+2*x^3+7*x^2-6*x+1])/(2*x), {x, 0, 20}], x] (* Vaclav Kotesovec, Mar 02 2014 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
STATUS
approved