Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1001-1111-1001 pattern in any orientation.
A146931
Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 1001-1111-1001 pattern in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =1a(7) =3a(8) =7a(9) =14a(10) =22a(11) =37a(12) =79a(13) =162a(14) =380a(15) =937a(16) =2496a(17) =7209a(18) =22236a(19) =73304a(20) =252500a(21) =902438a(22) =3477063a(23) =13836097a(24) =60384897a(25) =273397251a(26) =1352635265a(27) =7039542506a(28) =39611966803
External references
- oeis: A146931