a(n) = Sum_{k=0..floor(2*n/5)} binomial(2*k+1,2*n-5*k).

Terms

a(0) =1a(1) =0a(2) =0a(3) =3a(4) =1a(5) =1a(6) =10a(7) =5a(8) =7a(9) =35a(10) =22a(11) =37a(12) =126a(13) =95a(14) =174a(15) =463a(16) =408a(17) =770a(18) =1732a(19) =1742a(20) =3290a(21) =6584a(22) =7385a(23) =13760a(24) =25384a(25) =31078a(26) =56786a(27) =99043a(28) =129886a(29) =232393