OFFSET
1,2
COMMENTS
Conjecture: a(n) can be only 1, 2, or 3 (with the first occurrences of 3 appearing at n = 4, 9, 30, 327 and 3512).
LINKS
Paolo Xausa, Table of n, a(n) for n = 1..10000
Paolo Xausa, 1200 X 1200 raster image of a(n), n = 1..1440000, read left to right, top to bottom, showing a(n) = 1 in blue, a(n) = 2 in white and a(n) = 3 in red.
MATHEMATICA
With[{upto=1000}, Map[Length, Most[Split[PrimePi[Select[Range[upto], PrimePowerQ]]]]]] (* Considers prime powers up to 1000 *)
CROSSREFS
KEYWORD
nonn,changed
AUTHOR
Paolo Xausa, Oct 25 2023
STATUS
approved