Number of sets of nonempty words with a total of n letters over quaternary alphabet such that within each word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.
A340411
Number of sets of nonempty words with a total of n letters over quaternary alphabet such that within each word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =13a(4) =60a(5) =206a(6) =865a(7) =3408a(8) =15025a(9) =57175a(10) =240741a(11) =961035a(12) =4132903a(13) =16279273a(14) =68134510a(15) =274714351a(16) =1164578487a(17) =4657730815a(18) =19404869767a(19) =78676610521a(20) =330495175277
External references
- oeis: A340411