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

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =2a(7) =3a(8) =5a(9) =8a(10) =13a(11) =26a(12) =47a(13) =86a(14) =159a(15) =292a(16) =584a(17) =1121a(18) =2156a(19) =4153a(20) =8014a(21) =16028a(22) =31472a(23) =61823a(24) =121490a(25) =238827a(26) =477654a(27) =947294a(28) =1878560a(29) =3725648