Triangle read by rows: numbers of isomers of unbranched a-4-catapolyoctagons.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =1a(6) =3a(7) =4a(8) =4a(9) =1a(10) =9a(11) =16a(12) =16a(13) =4a(14) =1a(15) =39a(16) =85a(17) =84a(18) =32a(19) =7a(20) =1a(21) =169a(22) =439a(23) =465a(24) =210a(25) =57a(26) =7a(27) =1a(28) =819a(29) =2358