Number of alkyl benzenes with n carbon atoms: C(n)H(2n-6).

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =0a(5) =1a(6) =1a(7) =4a(8) =8a(9) =22a(10) =51a(11) =136a(12) =335a(13) =871a(14) =2217a(15) =5749a(16) =14837a(17) =38636a(18) =100622a(19) =263381a(20) =690709a(21) =1817544a(22) =4793449a(23) =12675741a(24) =33592349a(25) =89223734a(26) =237455566a(27) =633176939a(28) =1691377956a(29) =4525792533