Number of planar n-hexes, or polyhexes (in the sense of A000228, so rotations and reflections count as the same shape) with at least one hole.
A038144
Number of planar n-hexes, or polyhexes (in the sense of A000228, so rotations and reflections count as the same shape) with at least one hole.
Terms
- a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =1a(6) =2a(7) =13a(8) =67a(9) =404a(10) =2323a(11) =13517a(12) =76570a(13) =429320a(14) =2373965a(15) =13004323a(16) =70641985a(17) =381260615a(18) =2046521491a(19) =10936624026a(20) =58228136539a(21) =309048278652
External references
- oeis: A038144