A072586 Number of numbers <= n having prime factors with odd exponents only.

0, 1, 2, 2, 3, 4, 5, 6, 6, 7, 8, 8, 9, 10, 11, 11, 12, 12, 13, 13, 14, 15, 16, 17, 17, 18, 19, 19, 20, 21, 22, 23, 24, 25, 26, 26, 27, 28, 29, 30, 31, 32, 33, 33, 33, 34, 35, 35, 35, 35, 36, 36, 37, 38, 39, 40, 41, 42, 43, 43, 44, 45, 45, 45, 46, 47, 48, 48, 49, 50, 51, 51, 52

Offset

1,3

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Formula

a(n) ~ c * n , where c = A065463. - Amiram Eldar, Sep 18 2022

Mathematica

Accumulate @ Table[If[n > 1 && AllTrue[FactorInteger[n][[;; , 2]], OddQ], 1, 0], {n, 1, 100}] (* Amiram Eldar, Sep 18 2022 *)

Crossrefs

Cf. A000196, A002035, A065463, A295316.

Sequence in context: A331306 A119353 A140859 * A329548 A028391 A038668

Adjacent sequences: A072583 A072584 A072585 * A072587 A072588 A072589

Keyword

nonn

Author

Reinhard Zumkeller, Jun 23 2002

Status

approved