Number of compositions of n where each part i is marked with a word of length i over a binary alphabet whose letters appear in alphabetical order and both letters occur at least once in the composition.
A293579
Number of compositions of n where each part i is marked with a word of length i over a binary alphabet whose letters appear in alphabetical order and both letters occur at least once in the composition.
Terms
- a(0) =3a(1) =16a(2) =66a(3) =248a(4) =892a(5) =3136a(6) =10888a(7) =37536a(8) =128880a(9) =441472a(10) =1510176a(11) =5161856a(12) =17635264a(13) =60233728a(14) =205697152a(15) =702386688a(16) =2398283520a(17) =8188622848a(18) =27958448640a(19) =95457597440a(20) =325915589632
External references
- oeis: A293579