Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1111-0010-0010 pattern in any orientation.
A147174
Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1000-1111-0010-0010 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) =9a(10) =19a(11) =35a(12) =81a(13) =217a(14) =621a(15) =1903a(16) =7803a(17) =32967a(18) =151167a(19) =704477a(20) =3742519a(21) =21530169
External references
- oeis: A147174