Catacondensed simply-connected monopentapolyhexes.

Terms

a(0) =0a(1) =0a(2) =1a(3) =7a(4) =30a(5) =132a(6) =559a(7) =2416a(8) =10483a(9) =46072a(10) =204155a(11) =912779a(12) =4110644a(13) =18636572a(14) =84985825a(15) =389586145a(16) =1794268460a(17) =8298524480a(18) =38527095859a(19) =179487051589a(20) =838820171722