Symmetric matrix based on A007598(n+1), by antidiagonals.

Terms

a(0) =1a(1) =4a(2) =4a(3) =9a(4) =17a(5) =9a(6) =25a(7) =40a(8) =40a(9) =25a(10) =64a(11) =109a(12) =98a(13) =109a(14) =64a(15) =169a(16) =281a(17) =265a(18) =265a(19) =281a(20) =169a(21) =441a(22) =740a(23) =685a(24) =723a(25) =685a(26) =740a(27) =441a(28) =1156a(29) =1933