A061178 Third column (m=2) of triangle A060920 (bisection of Fibonacci triangle, even part).

1, 9, 51, 233, 942, 3522, 12473, 42447, 140109, 451441, 1426380, 4434420, 13599505, 41225349, 123723351, 368080793, 1086665562, 3186317718, 9286256393, 26916587307, 77634928209, 222920650081

Offset: 0

Author

Wolfdieter Lang, Apr 20 2001

Keywords

• nonn
• easy

Comments

Numerator polynomial of g.f. is sum(A061176(3,m)*x^m,m=0..3).

Crossrefs

A001519, A054444.

Formula

a(n)= A060920(n+2, 2).

G.f.: (1-x^3)/(1-3*x+x^2)^3.