Number of nonnegative integer matrices with 2 distinct columns and any number of nonzero rows with each column sum being n and rows in nonincreasing lexicographic order.

A331197

Number of nonnegative integer matrices with 2 distinct columns and any number of nonzero rows with each column sum being n and rows in nonincreasing lexicographic order.

Terms

    a(0) =0a(1) =1a(2) =7a(3) =28a(4) =104a(5) =332a(6) =1032a(7) =2983a(8) =8384a(9) =22622a(10) =59479a(11) =151902a(12) =379616a(13) =927521a(14) =2224100a(15) =5236410a(16) =12130549a(17) =27669296a(18) =62229605a(19) =138095206a(20) =302672402a(21) =655627183a(22) =1404598865a(23) =2977830134a(24) =6251059210a(25) =12999297747a(26) =26791987616a(27) =54750232180a(28) =110977385294a(29) =223204454700

External references