OFFSET
2,3
LINKS
Michael De Vlieger, Table of n, a(n) for n = 2..2919
R. A. Sulanke, Moments of generalized Motzkin paths, J. Integer Sequences, Vol. 3 (2000), #00.1.
FORMULA
G.f.: 1 / sqrt(1-4*z^2-2*z^3+z^6). - Sean A. Irvine, Dec 25 2021
MATHEMATICA
CoefficientList[Series[1/Sqrt[1 - 4 x^2 - 2 x^3 + x^6], {x, 0, 34}], x], (* Michael De Vlieger, Dec 25 2021 *)
CROSSREFS
KEYWORD
nonn,easy,nice
AUTHOR
N. J. A. Sloane, Jan 12 2000
EXTENSIONS
More terms from Reiner Martin, Oct 13 2002
Typos in terms corrected by Sean A. Irvine, Dec 25 2021
STATUS
approved