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A087560 Smallest m > n such that gcd(m, n^2) = n. 4
2, 6, 6, 12, 10, 30, 14, 24, 18, 30, 22, 60, 26, 42, 30, 48, 34, 90, 38, 60, 42, 66, 46, 120, 50, 78, 54, 84, 58, 210, 62, 96, 66, 102, 70, 180, 74, 114, 78, 120, 82, 210, 86, 132, 90, 138, 94, 240, 98, 150, 102, 156, 106, 270, 110, 168, 114, 174, 118, 420, 122 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Equals n multiplied by the least nontrivial number coprime to n. - Amarnath Murthy, Nov 20 2005

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

FORMULA

a(n) = n*A053669(n).

A000005(a(n)) = 2*A000005(n) = A062011(n). - Reinhard Zumkeller, May 17 2006

MATHEMATICA

Table[n*Select[Prime[Range[Log2[n] + 1]], ! Divisible[n, #] &][[1]], {n, 61}] (* Ivan Neretin, May 21 2015 *)

CROSSREFS

Cf. A119416.

Sequence in context: A106832 A129902 A350631 * A071892 A064797 A053319

Adjacent sequences: A087557 A087558 A087559 * A087561 A087562 A087563

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Oct 24 2003

STATUS

approved

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Last modified November 28 05:56 EST 2022. Contains 358407 sequences. (Running on oeis4.)