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

Terms

a(0) =1a(1) =0a(2) =0a(3) =2a(4) =0a(5) =3a(6) =3a(7) =0a(8) =12a(9) =4a(10) =5a(11) =30a(12) =5a(13) =30a(14) =60a(15) =13a(16) =105a(17) =105a(18) =63a(19) =280a(20) =177a(21) =260a(22) =630a(23) =342a(24) =849a(25) =1271a(26) =855a(27) =2320a(28) =2442a(29) =2475