Number of (n+2) X (1+2) 0..3 arrays with every 3 X 3 subblock row and column sum 3 or 6 and every diagonal and antidiagonal sum not 3 or 6.
A251772
Number of (n+2) X (1+2) 0..3 arrays with every 3 X 3 subblock row and column sum 3 or 6 and every diagonal and antidiagonal sum not 3 or 6.
Terms
- a(0) =470a(1) =1142a(2) =2402a(3) =4790a(4) =12302a(5) =27242a(6) =55766a(7) =148022a(8) =332738a(9) =688646a(10) =1847582a(11) =4175018a(12) =8671142a(13) =23345702a(14) =52842914a(15) =109873622a(16) =296146862a(17) =670682474a(18) =1395012278a(19) =3761354582a(20) =8519745410a(21) =17722964198a(22) =47791500542a(23) =108256965290
External references
- oeis: A251772