a(n) = Sum_{k=0..floor(3*n/5)} binomial(k,3*n-5*k).

Terms

a(0) =1a(1) =0a(2) =1a(3) =0a(4) =1a(5) =1a(6) =1a(7) =4a(8) =1a(9) =10a(10) =2a(11) =20a(12) =8a(13) =35a(14) =29a(15) =57a(16) =85a(17) =94a(18) =211a(19) =175a(20) =464a(21) =385a(22) =938a(23) =935a(24) =1808a(25) =2289a(26) =3459a(27) =5385a(28) =6826a(29) =12031