Number of sets of nonempty words with a total of n letters over quinary alphabet such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.
A293744
Number of sets of nonempty words with a total of n letters over quinary 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) =135a(7) =422a(8) =1357a(9) =4503a(10) =15301a(11) =53225a(12) =189070a(13) =684540a(14) =2522194a(15) =9441960a(16) =35867225a(17) =138080428a(18) =538155330a(19) =2121211604a(20) =8448577175a(21) =33974559322a(22) =137842934746a(23) =563885092371
External references
- oeis: A293744