A130092 Numbers with at least two factors having in their canonical prime factorization equal exponents.

6, 10, 14, 15, 21, 22, 26, 30, 33, 34, 35, 36, 38, 39, 42, 46, 51, 55, 57, 58, 60, 62, 65, 66, 69, 70, 74, 77, 78, 82, 84, 85, 86, 87, 90, 91, 93, 94, 95, 100, 102, 105, 106, 110, 111, 114, 115, 118, 119, 120, 122, 123, 126, 129, 130, 132, 133, 134, 138, 140, 141, 142

Offset

1,1

Comments

Complement of A130091; A120944 and A085986 are subsequences;

a(n)>A130091(n) for n<=150, a(n) < A130091(n) for n>150.

Links

R. Zumkeller, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Prime Factorization

Mathematica

t[n_] := FactorInteger[n][[All, 2]]; s = Select[Range[400], Union[t[#]] == Sort[t[#]] &] (* A130091 *)
Complement[Range[Max[s]], s]  (* A130092 *)
(* Clark Kimberling, Mar 12 2015 *)

Crossrefs

Sequence in context: A119899 A351295 A362606 * A289619 A329140 A362605

Adjacent sequences: A130089 A130090 A130091 * A130093 A130094 A130095

Keyword

nonn

Author

Reinhard Zumkeller, May 06 2007

Status

approved