6380241domain: NAppears in sequencesa(n) = Sum_{k <= n/2 } binomial(n-2k, 3k).at n=32A137356Number of compositions of 5*n-4 into parts 3 and 5.at n=19A369848a(n) = Sum_{k=0..floor(2*n/5)} binomial(2*n-2*k,3*k).at n=16A392401a(n) = Sum_{k=0..floor(2*n/3)} binomial(2*k,2*n-3*k).at n=24A392428