Number of (2+2) X (n+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 1, 2, 4, 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 1, 2, 4, 6 or 7.
A252560
Number of (2+2) X (n+2) 0..3 arrays with every 3 X 3 subblock row and diagonal sum equal to 1, 2, 4, 6 or 7 and every 3 X 3 column and antidiagonal sum not equal to 1, 2, 4, 6 or 7.
Terms
- a(0) =747a(1) =889a(2) =1752a(3) =3178a(4) =8508a(5) =21797a(6) =42359a(7) =123304a(8) =335953a(9) =649461a(10) =1947522a(11) =5522343a(12) =10600641a(13) =32456683a(14) =94716620a(15) =180887838a(16) =562002424a(17) =1672252134a(18) =3182740701a(19) =9984306730a(20) =30080613817a(21) =57127667585a(22) =180301146839a(23) =547401415073
External references
- oeis: A252560