545426

Appears in sequences

• Number of nX3 arrays containing 3 indistinguishable copies of 1..n with rows and columns in lexicographically strictly increasing order.at n=4A180837
• 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=25A180839