Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1000-1111-0100 pattern in any orientation.

A147121

Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1000-1000-1111-0100 pattern in any orientation.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =7a(8) =23a(9) =49a(10) =87a(11) =207a(12) =721a(13) =2133a(14) =8229a(15) =34269a(16) =162105a(17) =830967a(18) =4627991a(19) =26390809a(20) =175258607

External references