Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 3X3 tee 1,1 1,2 1,3 2,2 3,2 in any orientation.
A146012
Number of n X n binary arrays symmetric under 90 degree rotation with all ones connected only in a 3X3 tee 1,1 1,2 1,3 2,2 3,2 in any orientation.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =3a(6) =10a(7) =21a(8) =36a(9) =85a(10) =291a(11) =923a(12) =3735a(13) =16127a(14) =78677a(15) =397086a(16) =2338305a(17) =14669249a(18) =110594974a(19) =880940226a(20) =8350924404a(21) =83469619311a(22) =977221485292
External references
- oeis: A146012