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A182853 Squarefree composite integers and powers of squarefree composite integers. 9
6, 10, 14, 15, 21, 22, 26, 30, 33, 34, 35, 36, 38, 39, 42, 46, 51, 55, 57, 58, 62, 65, 66, 69, 70, 74, 77, 78, 82, 85, 86, 87, 91, 93, 94, 95, 100, 102, 105, 106, 110, 111, 114, 115, 118, 119, 122, 123, 129, 130, 133, 134, 138, 141, 142, 143, 145, 146, 154, 155, 158, 159, 161 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers that require exactly three iterations to reach a fixed point under the x -> A181819(x) map. In each case, 2 is the fixed point that is reached. (1 is the other fixed point of the x -> A181819(x) map.) Cf. A182850.

Numbers such that A001221(n) > 1 and A071625(n) = 1.

LINKS

Antti Karttunen, Table of n, a(n) for n = 1..10000

Eric Weisstein's World of Mathematics, Fixed Point

Eric Weisstein's World of Mathematics, Map

PROG

(Scheme)

(define A182853 (MATCHING-POS 1 1 (lambda (n) (= 3 (A182850 n))))) ;; After the alternative definition of the sequence given by the original author. Requires also MATCHING-POS macro from my IntSeq-library - Antti Karttunen, Feb 05 2016

(PARI) isoka(n) = (omega(n) > 1) && issquarefree(n); \\ A120944

isok(n) = isoka(n) || (ispower(n, , &k) && isoka(k)); \\ Michel Marcus, Jun 24 2017

CROSSREFS

Numbers n such that A182850(n) = 3. See also A182854, A182855.

Subsequence of A072774 and A182851.

Cf. A120944.

Sequence in context: A130092 A289619 A329140 * A212168 A080365 A000469

Adjacent sequences:  A182850 A182851 A182852 * A182854 A182855 A182856

KEYWORD

nonn,easy

AUTHOR

Matthew Vandermast, Jan 04 2011

STATUS

approved

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Last modified January 19 09:35 EST 2020. Contains 331048 sequences. (Running on oeis4.)