Number of nonnegative integer matrices with 2 columns and any number of distinct nonzero rows with column sums n.
A331646
Number of nonnegative integer matrices with 2 columns and any number of distinct nonzero rows with column sums n.
Terms
- a(0) =1a(1) =3a(2) =13a(3) =87a(4) =539a(5) =2483a(6) =14567a(7) =81669a(8) =402187a(9) =2089413a(10) =10344053a(11) =49065413a(12) =232941293a(13) =1092284091a(14) =5011510213a(15) =22637050383a(16) =100092546203a(17) =439274499155
External references
- oeis: A331646