Number of n X n binary arrays symmetric about the diagonal and under 90-degree rotation with all ones connected only in a tee 1,1 1,2 1,3 2,2 in any orientation.

A145930

Number of n X n binary arrays symmetric about the diagonal and under 90-degree rotation with all ones connected only in a tee 1,1 1,2 1,3 2,2 in any orientation.

Terms

    a(0) =1a(1) =1a(2) =1a(3) =1a(4) =2a(5) =1a(6) =4a(7) =1a(8) =10a(9) =3a(10) =38a(11) =10a(12) =203a(13) =33a(14) =1282a(15) =134a(16) =10692a(17) =947a(18) =122622a(19) =8780a(20) =1931387a(21) =97821a(22) =38646298a(23) =1375312a(24) =1027005070a(25) =27712816a(26) =36128007770a(27) =754977953a(29) =26645291289

External references