Number of sets of nonempty words with a total of n letters over nonary alphabet such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.
A293748
Number of sets of nonempty words with a total of n letters over nonary alphabet such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.
Terms
- a(0) =1a(1) =1a(2) =2a(3) =6a(4) =15a(5) =45a(6) =136a(7) =430a(8) =1415a(9) =4845a(10) =17234a(11) =63497a(12) =242720a(13) =958754a(14) =3916799a(15) =16493831a(16) =71586602a(17) =319336319a(18) =1463096806a(19) =6869041635a(20) =33014439494a(21) =162130576595a(22) =812715417240
External references
- oeis: A293748