Number of (n+2) X (2+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.
A251773
Number of (n+2) X (2+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) =1142a(1) =4182a(2) =12242a(3) =34934a(4) =132886a(5) =430730a(6) =1317638a(7) =5134774a(8) =17297338a(9) =54845894a(10) =214950374a(11) =737930314a(12) =2379309302a(13) =9343006742a(14) =32366662250a(15) =105198487910a(16) =413404292870
External references
- oeis: A251773