Erroneous version of A034320.

Terms

a(0) =1a(1) =0a(2) =2a(3) =2a(4) =3a(5) =4a(6) =5a(7) =6a(8) =8a(9) =10a(10) =12a(11) =15a(12) =18a(13) =22a(14) =27a(15) =32a(16) =38a(17) =46a(18) =54a(19) =64a(20) =76