Number of centered hydrocarbons with n atoms.

Terms

a(0) =0a(1) =1a(2) =0a(3) =1a(4) =1a(5) =2a(6) =2a(7) =6a(8) =9a(9) =20a(10) =37a(11) =86a(12) =181a(13) =422a(14) =943a(15) =2223a(16) =5225a(17) =12613a(18) =30513a(19) =74883a(20) =184484a(21) =458561a(22) =1145406a(23) =2879870a(24) =7274983a(25) =18471060a(26) =47089144a(27) =120528657a(28) =309576725a(29) =797790928