Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a one by five or five by one block.

A145967

Number of n X n binary arrays symmetric about main diagonal with all ones connected only in a one by five or five by one block.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =3a(6) =8a(7) =27a(8) =89a(9) =333a(10) =1310a(11) =7293a(12) =48975a(13) =401989a(14) =3756663a(15) =40465266a(16) =497724568a(17) =7379658407a(18) =131602632698

External references