Number of 3X3 0..n arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under 90 degree rotation.

A187529

Number of 3X3 0..n arrays with each 2X2 subblock determinant nonzero and the array of 2X2 subblock determinants symmetric under 90 degree rotation.

Terms

    a(0) =0a(1) =8a(2) =74a(3) =280a(4) =784a(5) =1970a(6) =3580a(7) =6946a(8) =11726a(9) =19100a(10) =27672a(11) =44092a(12) =58988a(13) =83340a(14) =116344a(15) =156470a(16) =193434a(17) =262028a(18) =316330a(19) =414216a(20) =517530a(21) =629058a(22) =735548a(23) =935702a(24) =1100836a(25) =1299196a(26) =1530340a(27) =1835766a(28) =2068728a(29) =2511536

External references