A085359 Third self-convolution of A085357 (residues of binomial(3k,k)/(2k+1) modulo 2).

1, 3, 6, 7, 9, 12, 16, 15, 15, 21, 30, 30, 28, 30, 36, 31, 27, 33, 48, 51, 51, 54, 66, 60, 52, 60, 78, 76, 66, 66, 76, 63, 51, 57, 78, 81, 81, 90, 114, 105, 93, 111, 144, 138, 120, 126, 150, 126, 100, 108, 144, 148, 138, 138, 166, 150, 126, 138, 174, 168, 142, 138, 156

Offset: 0

Author

Paul D. Hanna, Jun 25 2003

Keywords

• nonn

Comments

a(n) - A085357(n-1) is always even for n > 0.

Crossrefs

Cf. A001764 (ternary trees), A085357.

Formula

G.f.: 1 + x*A(x) = A085357(x)^3 (mod 2), where A085357(x) = Sum_{k>=0} A085357(k)*x^k.