Erroneous version of A039952.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =6a(5) =7a(6) =12a(7) =15a(8) =20a(9) =30a(10) =31a(11) =60a(12) =61a(13) =84a(14) =105a(15) =140a(16) =210a(17) =211a(18) =420a(19) =421a(20) =422a(21) =423a(22) =840a(23) =841a(24) =1260a(25) =1261a(26) =1540a(27) =2310a(28) =2520a(29) =4620