Number of alkyls Y^{II} C_n H_{2n+2} with n carbon atoms.

Terms

a(0) =1a(1) =2a(2) =3a(3) =6a(4) =13a(5) =28a(6) =62a(7) =144a(8) =338a(9) =810a(10) =1970a(11) =4852a(12) =12073a(13) =30334a(14) =76805a(15) =195850a(16) =502461a(17) =1296122a(18) =3359527a(19) =8745744a(20) =22856223a(21) =59944156a(22) =157718380a(23) =416189954a(24) =1101204387a(25) =2920914484a(26) =7765357967a(27) =20688204244a(28) =55225188289a(29) =147688302518