Number of nonnegative integer matrices with n distinct columns and any number of distinct nonzero rows with column sums 2 and columns in decreasing lexicographic order.
A331704
Number of nonnegative integer matrices with n distinct columns and any number of distinct nonzero rows with column sums 2 and columns in decreasing lexicographic order.
Terms
- a(0) =1a(1) =1a(2) =6a(3) =46a(4) =544a(5) =7983a(6) =144970a(7) =3097825a(8) =76494540a(9) =2139610590a(10) =66898897827
External references
- oeis: A331704