Word structures of length n using a 5-ary alphabet.

Terms

a(0) =1a(1) =1a(2) =2a(3) =5a(4) =15a(5) =52a(6) =202a(7) =855a(8) =3845a(9) =18002a(10) =86472a(11) =422005a(12) =2079475a(13) =10306752a(14) =51263942a(15) =255514355a(16) =1275163905a(17) =6368612302a(18) =31821472612a(19) =159042661905a(20) =795019337135