Kekulé numbers for certain benzenoids (see the Cyvin-Gutman book for details).

Terms

a(0) =1a(1) =4a(2) =30a(3) =146a(4) =517a(5) =1476a(6) =3614a(7) =7890a(8) =15761a(9) =29332a(10) =51526a(11) =86274a(12) =138725a(13) =215476a(14) =324822a(15) =477026a(16) =684609a(17) =962660a(18) =1329166a(19) =1805362a(20) =2416101a(21) =3190244a(22) =4161070a(23) =5366706a(24) =6850577a(25) =8661876a(26) =10856054a(27) =13495330a(28) =16649221a(29) =20395092