A265693 Squarefree composites that are not sqrt(n)-smooth: some prime factor of n is > sqrt(n).

6, 10, 14, 15, 21, 22, 26, 33, 34, 35, 38, 39, 42, 46, 51, 55, 57, 58, 62, 65, 66, 69, 74, 77, 78, 82, 85, 86, 87, 91, 93, 94, 95, 102, 106, 110, 111, 114, 115, 118, 119, 122, 123, 129, 130, 133, 134, 138, 141, 142, 143, 145, 146, 155, 158, 159, 161, 166, 170, 174

Offset

1,1

Comments

Intersection of A064052 and A120944. - Michel Marcus, Dec 15 2015

Links

Robert Israel, Table of n, a(n) for n = 1..10000

Example

a(13) = 42 = 2*3*7. It is squarefree, composite and 7 > sqrt(42) = 6.4807...

Maple

filter:= proc(n)
  if isprime(n) or not numtheory:-issqrfree(n) then return false fi;
  max(numtheory:-factorset(n))^2 > n
end proc:
select(filter, [$2..1000]); # Robert Israel, Nov 04 2019

Mathematica

JaggedQ[n_] := If[Last[FactorInteger[n]][[1]]>Sqrt[n], True, False]; Select[Range[200], JaggedQ[#]&&SquareFreeQ[#]&&!PrimeQ[#] &]

Prog

(PARI) lista(nn) = {forcomposite(n=1, nn, if (issquarefree(n), my(f = factor(n)); if (f[#f~, 1]^2 > n, print1(n, ", "))); ); } \\ Michel Marcus, Dec 15 2015

Crossrefs

Cf. A005117, A064052, A120944.

Includes A006881.

Sequence in context: A238748 A367590 A268390 * A211484 A339561 A350486

Adjacent sequences: A265690 A265691 A265692 * A265694 A265695 A265696

Keyword

nonn

Author

Frank M Jackson, Dec 13 2015

Status

approved