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A069186 Numbers n such that core(n)=floor(sqrt(n)), where core(x)=A007913(x) is the squarefree part of x and floor(sqrt(x))=A000196(x). 1
1, 8, 12, 63, 224, 240, 575, 1224, 1260, 2303, 3968, 6399, 14399, 20448, 20592, 28223, 38024, 38220, 50175, 65024, 65280, 82943, 104328, 104652, 129599, 159200, 159600, 193599, 233288, 233772, 278783, 330624, 389375, 455624 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Apart from 1, numbers of the form x*y^2 for y >= 2, where x is squarefree and is either y^2-2 or y^2-1. - Robert Israel, Apr 11 2019

LINKS

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

MAPLE

select(numtheory:-issqrfree, [1, seq(seq(b^2+j, j=-2..-1), b=2..100)]); # Robert Israel, Apr 11 2019

PROG

(PARI) isok(n) = core(n) == sqrtint(n); \\ Michel Marcus, Apr 12 2019

CROSSREFS

Cf. A000196, A007913.

Sequence in context: A212815 A298901 A305236 * A166625 A038290 A002288

Adjacent sequences:  A069183 A069184 A069185 * A069187 A069188 A069189

KEYWORD

easy,nonn

AUTHOR

Benoit Cloitre, Apr 14 2002

EXTENSIONS

Name edited by Robert Israel, Apr 12 2019

STATUS

approved

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Last modified October 16 03:37 EDT 2019. Contains 328040 sequences. (Running on oeis4.)