Number of free asymmetrical polyhexes with n cells.

Terms

a(0) =0a(1) =0a(2) =0a(3) =2a(4) =10a(5) =57a(6) =279a(7) =1338a(8) =6329a(9) =29969a(10) =142461a(11) =680637a(12) =3269716a(13) =15785281a(14) =76557773a(15) =372812193a(16) =1822122394a(17) =8934639920a(18) =43938614933a(19) =216649723022