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A333535 Card{ k<=n, k such that all prime divisors of k are < sqrt(k) }. 6
0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 4, 4, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 7, 7, 8, 8, 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 13, 14, 14, 15, 15, 15, 15, 16, 16, 16, 17, 18, 18, 18, 18, 18, 18, 19, 19, 20, 20, 20, 21, 21, 21, 21, 21, 22, 23, 23, 23, 24, 24, 24, 24, 24, 24, 25 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,12
LINKS
MAPLE
a:=[];
for n from 1 to 100 do
c:=0;
for m from 1 to n do
if A006530(m)^2 < m then c:=c+1; fi; od:
a:=[op(a), c];
od:
a;
# second Maple program:
a:= proc(n) option remember; `if`(n<2, 0, a(n-1)+
`if`(max(map(i-> i[1], ifactors(n)[2]))^2<n, 1, 0))
end:
seq(a(n), n=1..100); # Alois P. Heinz, Apr 10 2020
MATHEMATICA
a[1] = 0;
a[n_] := a[n] = a[n-1] + Boole[Max[FactorInteger[n][[All, 1]]]^2 < n];
Array[a, 100] (* Jean-François Alcover, Nov 01 2020 *)
CROSSREFS
The following are all different versions of sqrt(n)-smooth numbers: A048098, A063539, A064775, A295084, A333535, A333536.
Sequence in context: A087866 A061392 A048273 * A364678 A175387 A024542
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Apr 10 2020
STATUS
approved

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Last modified March 29 09:59 EDT 2024. Contains 371268 sequences. (Running on oeis4.)