Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 0100-0100-1111-0010 pattern in any orientation.

A147031

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 0100-0100-1111-0010 pattern in any orientation.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =1a(8) =5a(9) =13a(10) =25a(11) =43a(12) =89a(13) =283a(14) =1197a(15) =5015a(16) =19569a(17) =70793a(18) =320835a(19) =1805563a(20) =12416113a(21) =87073927

External references