Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1010-1111-1000 pattern in any orientation.
A146646
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1010-1111-1000 pattern in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =7a(9) =13a(10) =27a(11) =41a(12) =115a(13) =303a(14) =1555a(15) =4709a(16) =23865a(17) =76741a(18) =449473a(19) =1923409a(20) =15857735a(21) =84725491
External references
- oeis: A146646