Triangle read by rows: T(n,k) is the number of irreducible words covering the alphabet [n] such that the maximal cardinality of C is k, where C is a subset of the alphabet such that all letters in C appear in weakly increasing order within the word.
A390670
Triangle read by rows: T(n,k) is the number of irreducible words covering the alphabet [n] such that the maximal cardinality of C is k, where C is a subset of the alphabet such that all letters in C appear in weakly increasing order within the word.
Terms
- a(0) =1a(1) =0a(2) =1a(3) =0a(4) =1a(5) =1a(6) =0a(7) =2a(8) =4a(9) =1a(10) =0a(11) =9a(12) =15a(13) =9a(14) =1a(15) =0a(16) =80a(17) =79a(18) =64a(19) =16a(20) =1a(21) =0a(22) =1226a(23) =705a(24) =471a(25) =185a(26) =25a(27) =1a(28) =0a(29) =29215
External references
- oeis: A390670