Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 2 5 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 0 2 5 6 or 7.

A252508

Number of (n+2)X(2+2) 0..3 arrays with every 3X3 subblock row and column sum equal to 0 2 5 6 or 7 and every 3X3 diagonal and antidiagonal sum not equal to 0 2 5 6 or 7.

Terms

    a(0) =1515a(1) =1644a(2) =3980a(3) =9277a(4) =25197a(5) =76113a(6) =231372a(7) =698936a(8) =2121821a(9) =6483996a(10) =19881260a(11) =61024374a(12) =187473423a(13) =576442523a(14) =1773336035a(15) =5457204006a(16) =16797726720a(17) =51712080105a(18) =159214729408a(19) =490238324306

External references