Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1100-0111-0011 pattern in any orientation.
A147214
Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1100-0111-0011 pattern in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =1a(9) =1a(10) =3a(11) =3a(12) =9a(13) =9a(14) =23a(15) =23a(16) =55a(17) =55a(18) =315a(19) =315a(20) =2117a(21) =2117a(22) =14227
External references
- oeis: A147214