Number of nonnegative integer 2 X 2 matrices with sum of elements equal to n, under row and column permutations.

A053307

Number of nonnegative integer 2 X 2 matrices with sum of elements equal to n, under row and column permutations.

Terms

    a(0) =1a(1) =1a(2) =4a(3) =5a(4) =11a(5) =14a(6) =24a(7) =30a(8) =45a(9) =55a(10) =76a(11) =91a(12) =119a(13) =140a(14) =176a(15) =204a(16) =249a(17) =285a(18) =340a(19) =385a(20) =451a(21) =506a(22) =584a(23) =650a(24) =741a(25) =819a(26) =924a(27) =1015a(28) =1135a(29) =1240

External references