Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-1111-0100-0100 pattern in any orientation.

A147471

Number of n X n binary arrays symmetric about both diagonal and antidiagonal with all ones connected only in a 1100-1111-0100-0100 pattern in any orientation.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =3a(6) =3a(7) =9a(8) =15a(9) =33a(10) =57a(11) =163a(12) =337a(13) =1301a(14) =3059a(15) =12941a(16) =34215a(17) =171133a(18) =573633a(19) =3343793a(20) =12826849a(21) =85459189a(22) =371588907a(23) =2938061259a(24) =15238544087a(25) =143663828309

External references