a(1)=0; for n>1, a(n) = number of isomeric hydrocarbons of the acetylene series with carbon content n.
A000642
a(1)=0; for n>1, a(n) = number of isomeric hydrocarbons of the acetylene series with carbon content n.
Terms
- a(0) =0a(1) =1a(2) =1a(3) =2a(4) =3a(5) =7a(6) =14a(7) =32a(8) =72a(9) =171a(10) =405a(11) =989a(12) =2426a(13) =6045a(14) =15167a(15) =38422a(16) =97925a(17) =251275a(18) =648061a(19) =1679869a(20) =4372872a(21) =11428365a(22) =29972078a(23) =78859809a(24) =208094977a(25) =550603722a(26) =1460457242a(27) =3882682803a(28) =10344102122a(29) =27612603765
External references
- oeis: A000642