Number of trisubstituted linear alkanes of composition C_n H_(2n-1) XYZ.

Terms

a(0) =8a(1) =32a(2) =92a(3) =212a(4) =416a(5) =728a(6) =1172a(7) =1772a(8) =2552a(9) =3536a(10) =4748a(11) =6212a(12) =7952a(13) =9992a(14) =12356a(15) =15068a(16) =18152a(17) =21632a(18) =25532a(19) =29876a(20) =34688a(21) =39992a(22) =45812a(23) =52172a(24) =59096a(25) =66608a(26) =74732a(27) =83492a(28) =92912a(29) =103016