1573764

Appears in sequences

• Number of nX2 arrays containing 2 indistinguishable copies of 1..n with rows and columns in lexicographically strictly increasing order.at n=7A180836
• T(n,k) = number of n X k arrays containing k indistinguishable copies of 1..n with rows and columns in lexicographically strictly increasing order.at n=43A180839