Number of nonnegative integer matrices with n distinct columns and any number of distinct nonzero rows with each column sum being 2 and rows in decreasing lexicographic order.
A331316
Number of nonnegative integer matrices with n distinct columns and any number of distinct nonzero rows with each column sum being 2 and rows in decreasing lexicographic order.
Terms
- a(0) =1a(1) =1a(2) =4a(3) =27a(4) =266a(5) =3599a(6) =62941a(7) =1372117a(8) =36248765a(9) =1135864306a(10) =41501271477
External references
- oeis: A331316