Number of monosubstituted alkanes C(n-1)H(2n-1)-X with n-1 carbon atoms that are stereoisomers.

Terms

a(0) =0a(1) =0a(2) =0a(3) =0a(4) =2a(5) =6a(6) =20a(7) =60a(8) =176a(9) =512a(10) =1488a(11) =4326a(12) =12648a(13) =37186a(14) =109980a(15) =327216a(16) =979020a(17) =2944414a(18) =8897732a(19) =27005290a(20) =82288516a(21) =251650788a(22) =772127678a(23) =2376238138a(24) =7333188770a(25) =22688297950a(26) =70360977228a(27) =218678818026a(28) =681017928476