Number of spiro bicyclic skeletons with n carbon atoms (see Parks et al. for precise definition).

A121158

Number of spiro bicyclic skeletons with n carbon atoms (see Parks et al. for precise definition).

Terms

    a(0) =1a(1) =1a(2) =5a(3) =10a(4) =34a(5) =82a(6) =240a(7) =630a(8) =1764a(9) =4752a(10) =13108a(11) =35703a(12) =98108a(13) =268553a(14) =737864a(15) =2025779a(16) =5572160a(17) =15331017a(18) =42230755a(19) =116395955a(20) =321089489a(21) =886320404a(22) =2448312482a(23) =6767186801a(24) =18716207007a(25) =51792971141a(26) =143403624284a(27) =397254931272

External references