Number of ordered rooted trees with n non-root nodes and all outdegrees <= five.

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =14a(5) =42a(6) =131a(7) =421a(8) =1385a(9) =4642a(10) =15795a(11) =54418a(12) =189454a(13) =665471a(14) =2355510a(15) =8393461a(16) =30084695a(17) =108394449a(18) =392356788a(19) =1426137550a(20) =5203211200a(21) =19048447855a(22) =69951072700a(23) =257609070810a(24) =951172531880