Kekulé numbers for certain benzenoids.

Terms

a(0) =1a(1) =19a(2) =142a(3) =664a(4) =2330a(5) =6726a(6) =16848a(7) =37884a(8) =78243a(9) =150865a(10) =274846a(11) =477412a(12) =796276a(13) =1282412a(14) =2003280a(15) =3046536a(16) =4524261a(17) =6577743a(18) =9382846a(19) =13156000a(20) =18160846a(21) =24715570a(22) =33200960a(23) =44069220a(24) =57853575a(25) =75178701a(26) =96772014a(27) =123475852