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

Terms

a(0) =1a(1) =0a(2) =0a(3) =2a(4) =0a(5) =1a(6) =3a(7) =0a(8) =4a(9) =4a(10) =1a(11) =10a(12) =5a(13) =6a(14) =20a(15) =7a(16) =21a(17) =35a(18) =15a(19) =56a(20) =57a(21) =44a(22) =126a(23) =94a(24) =129a(25) =253a(26) =175a(27) =340a(28) =474a(29) =385