Triangle read by rows: T(n,k) is the number of distinct tuples E each corresponding to some k-ary word W = (w_1, ..., w_n), where E is a tuple (e_1, ..., e_{n-1}) with e_i being the number of pairs of equal letters (w_j,w_k) in W such that j + i = k.

A381349

Triangle read by rows: T(n,k) is the number of distinct tuples E each corresponding to some k-ary word W = (w_1, ..., w_n), where E is a tuple (e_1, ..., e_{n-1}) with e_i being the number of pairs of equal letters (w_j,w_k) in W such that j + i = k.

Terms

    a(0) =1a(1) =1a(2) =2a(3) =1a(4) =3a(5) =4a(6) =1a(7) =6a(8) =9a(9) =10a(10) =1a(11) =10a(12) =22a(13) =26a(14) =27a(15) =1a(16) =20a(17) =54a(18) =73a(19) =78a(20) =79a(21) =1a(22) =36a(23) =163a(24) =249a(25) =269a(26) =275a(27) =276a(28) =1a(29) =72

External references