Number of free pure achiral multifunctions with one atom and n positions.

Terms

a(0) =1a(1) =0a(2) =1a(3) =1a(4) =3a(5) =4a(6) =10a(7) =17a(8) =37a(9) =70a(10) =150a(11) =299a(12) =634a(13) =1311a(14) =2786a(15) =5879a(16) =12584a(17) =26904a(18) =58005a(19) =125242a(20) =271819a(21) =591297a(22) =1290976a(23) =2825170a(24) =6199964a(25) =13635749a(26) =30057649a(27) =66386206a(28) =146903289a(29) =325637240