4154403

Appears in sequences

• Convolution of A000108 (Catalan numbers) with A020920.at n=7A045492
• a(0) = 0, thereafter, a(n) = 2^(2*n-1)*( binomial((3*n-1)/2,n) - binomial(3*n/2, n)/3 ).at n=8A244469