Number of free hexagonal polygons of symmetry class C_(2v) and area n.

Terms

a(0) =0a(1) =0a(2) =1a(3) =1a(4) =9a(5) =12a(6) =39a(7) =61a(8) =178a(9) =274a(10) =796a(11) =1251a(12) =3578a(13) =5692a(14) =16290a(15) =26069a(16) =74980a(17) =120676a(18) =348564a(19) =563503a(20) =1635175a(21) =2652445a(22) =7729807a(23) =12574028a(24) =36784467a(25) =59975232a(26) =176063801a(27) =287613473a(28) =846967739a(29) =1385815492