Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only either as two by three or three by two blocks.
A146157
Number of n X n binary arrays symmetric about the diagonal and under 90 degree rotation with all ones connected only either as two by three or three by two blocks.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =2a(7) =2a(8) =3a(9) =3a(10) =6a(11) =7a(12) =16a(13) =23a(14) =50a(15) =65a(16) =176a(17) =221a(18) =727a(19) =1056a(20) =3742a(21) =5997a(22) =23258a(23) =37914a(24) =168488a(25) =284282a(26) =1460179a(27) =2612520a(28) =15176540a(29) =28767703
External references
- oeis: A146157