Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1001-1111-1001 pattern in any orientation.

A146928

Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a 1001-1111-1001 pattern in any orientation.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =3a(7) =7a(8) =13a(9) =26a(10) =70a(11) =233a(12) =869a(13) =3436a(14) =14680a(15) =71757a(16) =413520a(17) =2721699a(18) =19996282a(19) =163378650a(20) =1508376980a(21) =15870814986a(22) =189905190363

External references