a(n) is the number of free unholey polyominoes of n cells with 90-degree rotational symmetry and no other.
A357647
a(n) is the number of free unholey polyominoes of n cells with 90-degree rotational symmetry and no other.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =0a(6) =0a(7) =1a(8) =0a(9) =0a(10) =0a(11) =2a(12) =2a(13) =0a(14) =0a(15) =7a(16) =7a(17) =0a(18) =0a(19) =22a(20) =24a(21) =0a(22) =0a(23) =71a(24) =82a(25) =0a(26) =0a(27) =239a(28) =280a(29) =0
External references
- oeis: A357647