Number of sets of nonempty words with a total of n letters over quinary alphabet containing the fifth letter such that within each prefix of a word every letter of the alphabet is at least as frequent as the subsequent alphabet letter.
A293886
Number of sets of nonempty words with a total of n letters over quinary alphabet containing the fifth 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) =6a(2) =36a(3) =172a(4) =813a(5) =3576a(6) =15647a(7) =66493a(8) =282063a(9) =1181554a(10) =4951592a(11) =20648077a(12) =86254964a(13) =359920291a(14) =1505749933a(15) =6305449303a(16) =26485669295a(17) =111485395542a(18) =470834817242
External references
- oeis: A293886