Number of nX4 arrays containing 4 indistinguishable copies of 1..n with rows and columns in lexicographically strictly increasing order.
A180838
Number of nX4 arrays containing 4 indistinguishable copies of 1..n with rows and columns in lexicographically strictly increasing order.
Terms
- a(0) =1a(1) =1a(2) =472a(3) =300888a(4) =333191079a(5) =637698093267
External references
- oeis: A180838