Number of nonnegative integer matrices with 2 columns and any number of distinct nonzero rows with column sums n and columns in nonincreasing lexicographic order.
A331711
Number of nonnegative integer matrices with 2 columns and any number of distinct nonzero rows with column sums n and columns in nonincreasing lexicographic order.
Terms
- a(0) =1a(1) =2a(2) =7a(3) =45a(4) =271a(5) =1244a(6) =7289a(7) =40841a(8) =201103a(9) =1044720a(10) =5172055a(11) =24532739a(12) =116470697a(13) =546142112a(14) =2505755203a(15) =11318525367a(16) =50046273319a(17) =219637249886a(18) =944072864849
External references
- oeis: A331711