Number of n X n binary arrays symmetric about the diagonal and under 90-degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.

A145762

Number of n X n binary arrays symmetric about the diagonal and under 90-degree rotation with all ones connected only either three adjacent vertically or three adjacent horizontally.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =4a(7) =1a(8) =11a(9) =3a(10) =36a(11) =8a(12) =178a(13) =27a(14) =1006a(15) =96a(16) =7478a(17) =569a(18) =70926a(19) =4093a(20) =898687a(21) =37611a(22) =14257237a(23) =421080a(24) =292647869a(25) =6366190a(26) =7706237478a(27) =123605120a(28) =263373760591a(29) =3088656877

External references