Number of nonnegative integer 2 X 2 matrices with no zero rows or columns and with sum of elements equal to n, up to row and column permutation.
A054974
Number of nonnegative integer 2 X 2 matrices with no zero rows or columns and with sum of elements equal to n, up to row and column permutation.
Terms
- a(0) =1a(1) =2a(2) =6a(3) =9a(4) =17a(5) =23a(6) =36a(7) =46a(8) =65a(9) =80a(10) =106a(11) =127a(12) =161a(13) =189a(14) =232a(15) =268a(16) =321a(17) =366a(18) =430a(19) =485a(20) =561a(21) =627a(22) =716a(23) =794a(24) =897a(25) =988a(26) =1106a(27) =1211a(28) =1345a(29) =1465
External references
- oeis: A054974