Number of n X n binary arrays symmetric under horizontal and vertical reflection with all ones connected only in a tee 1,1 1,2 1,3 2,2 in any orientation.
A145927
Number of n X n binary arrays symmetric under horizontal and vertical reflection 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) =6a(5) =1a(6) =38a(7) =9a(8) =408a(9) =33a(10) =7604a(11) =404a(12) =271731a(13) =7941a(14) =15992426a(15) =262632a(16) =1666574068a(17) =14831415a(18) =309972197784a(19) =1538127410a(21) =275592188347
External references
- oeis: A145927