Triangular array read by rows. T(n,k) is the number of 2 tuple lists of length n that have exactly k coincidences; n >= 0, 0 <= k <= n.

A226780

Triangular array read by rows. T(n,k) is the number of 2 tuple lists of length n that have exactly k coincidences; n >= 0, 0 <= k <= n.

Terms

    a(0) =1a(1) =0a(2) =1a(3) =3a(4) =0a(5) =1a(6) =26a(7) =9a(8) =0a(9) =1a(10) =453a(11) =104a(12) =18a(13) =0a(14) =1a(15) =11844a(16) =2265a(17) =260a(18) =30a(19) =0a(20) =1a(21) =439975a(22) =71064a(23) =6795a(24) =520a(25) =45a(26) =0a(27) =1a(28) =22056222a(29) =3079825

External references