Number of polyhexes with n cells that do not tile the plane.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =5a(6) =39a(7) =394a(8) =2784a(9) =19164a(10) =118762a(11) =579460a(12) =3110267a(13) =15264387a(14) =75007623a(15) =369928203a(16) =1817475619a(17) =8913862144a(18) =43914857957a(19) =216555328193