Number of sets of nonempty words with a total of n letters over binary alphabet containing the second letter such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.
A293883
Number of sets of nonempty words with a total of n letters over binary alphabet containing the second letter 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) =3a(2) =8a(3) =20a(4) =47a(5) =106a(6) =237a(7) =522a(8) =1146a(9) =2485a(10) =5406a(11) =11644a(12) =25157a(13) =53964a(14) =116003a(15) =247987a(16) =530999a(17) =1131889a(18) =2415431a(19) =5135838a(20) =10927816a(21) =23182209a(22) =49199697a(23) =104154808a(24) =220543306a(25) =465996956a(26) =984704338a(27) =2076988457a(28) =4380764354a(29) =9225209588
External references
- oeis: A293883