Number of (1+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 4 6 or 7.

A252559

Number of (1+2)X(n+2) 0..3 arrays with every 3X3 subblock row and diagonal sum equal to 1 2 4 6 or 7 and every 3X3 column and antidiagonal sum not equal to 1 2 4 6 or 7.

Terms

    a(0) =771a(1) =1107a(2) =1510a(3) =2443a(4) =4284a(5) =7755a(6) =13917a(7) =27182a(8) =51187a(9) =94813a(10) =189576a(11) =362736a(12) =678322a(13) =1360865a(14) =2614578a(15) =4907897a(16) =9838034a(17) =18931643a(18) =35616087a(19) =71259620a(20) =137248851a(21) =258672971a(22) =516507423a(23) =995487746a(24) =1879267853a(25) =3745133076

External references