a(n+1) = Sum_{k=0..floor(4*n/5)} a(k) * a(n-k).

Terms

a(0) =1a(1) =1a(2) =1a(3) =2a(4) =4a(5) =9a(6) =21a(7) =42a(8) =97a(9) =233a(10) =570a(11) =1414a(12) =3319a(13) =8208a(14) =20595a(15) =52370a(16) =133955a(17) =328261a(18) =833652a(19) =2136155a(20) =5519116a(21) =14341917a(22) =36069212a(23) =93074465a(24) =241613666a(25) =630653714a(26) =1652472131a(27) =4215072482a(28) =10985970447a(29) =28756470626