OFFSET
1,3
MATHEMATICA
rad[n_] := rad[n] = Times @@ FactorInteger[n][[All, 1]];
t = Select[Range[2^12], Nor[SquareFreeQ[#], PrimePowerQ[#]] &];
s = Select[t, #1/#2 >= #3 & @@ {#1, Times @@ #2, #2[[2]]} & @@ {#, FactorInteger[#][[All, 1]]} &];
{0}~Join~Union@ FoldList[Max, Table[m = s[[n]]; r = rad[m];
Count[TakeWhile[t, # < m &], _?(And[rad[#] == r, Mod[m, #] != 0] &)], {n, Length[s]}]]
CROSSREFS
KEYWORD
nonn
AUTHOR
Michael De Vlieger, Mar 05 2023
STATUS
approved