Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1000-1100-0110-0011 pattern in any orientation.
A147144
Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only in a 1000-1100-0110-0011 pattern in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =3a(9) =3a(10) =7a(11) =7a(12) =17a(13) =17a(14) =39a(15) =39a(16) =127a(17) =127a(18) =681a(19) =681a(20) =3913a(21) =3913a(22) =21369a(23) =21369a(24) =147701a(25) =147701a(26) =1344439a(27) =1344439a(28) =15252227
External references
- oeis: A147144