Number of n X n binary arrays symmetric under 90-degree rotation with all ones connected only in two by two blocks.

A145863

Number of n X n binary arrays symmetric under 90-degree rotation with all ones connected only in two by two blocks.

Terms

    a(0) =1a(1) =2a(2) =1a(3) =2a(4) =2a(5) =7a(6) =7a(7) =22a(8) =24a(9) =108a(10) =150a(11) =786a(12) =1301a(13) =8045a(14) =15509a(15) =116985a(16) =273970a(17) =2472105a(18) =6959192a(19) =74864863a(20) =250693524a(21) =3242639202a(22) =13050355068a(23) =202176993015a(24) =975396539666

External references