At 06:43 PM 6/9/2005, David Wilson wrote: >Can we extend A053878 out far enough to show it is not multiplicative? a(52) = 2 (the ratio is 17/15), but a(4)=1 and a(13)=1, so it is not multiplicitive. The first few non-zero terms are #25, 52, 53, 54, 64, which are 7, 2, 3, 5, 4 (resp),