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A075393 Positive integers n such that n is not divisible by A002034(n). 1
9, 16, 25, 45, 49, 75, 80, 121, 125, 147, 169, 175, 225, 243, 245, 250, 256, 289, 343, 361, 363, 441, 486, 500, 507, 512, 525, 529, 539, 605, 625, 637, 675, 686, 729, 735, 768, 841, 845, 847, 867, 875, 961, 1000, 1024, 1083, 1089, 1183, 1215, 1225, 1250 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

If n is squarefree, then A002034(n) is the largest prime factor of n, so n is not in the sequence. If p is an odd prime, then A002034(p^2) = 2*p, so p^2 is in the sequence. - David Wasserman, Jan 17 2005

LINKS

Table of n, a(n) for n=1..51.

EXAMPLE

a(1)=9 because 9 is the first number that is not a multiple of A002034(9)=6.

MATHEMATICA

(A002034[n_] := (m=1; While[ !IntegerQ[m!/n], m++ ]; m); list = {}; Do[If[ !IntegerQ[n/A002034[n]], list = Append[list, n]], {n, 100}]; list) - Jonathan Sondow, Apr 18 2004

CROSSREFS

Cf. A002034.

Sequence in context: A177430 A256705 A092941 * A161183 A183345 A303873

Adjacent sequences:  A075390 A075391 A075392 * A075394 A075395 A075396

KEYWORD

nonn

AUTHOR

Amarnath Murthy, Sep 22 2002

EXTENSIONS

More terms from David Wasserman, Jan 17 2005

Edited by N. J. A. Sloane, Apr 19 2007

STATUS

approved

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Last modified February 18 21:20 EST 2020. Contains 332028 sequences. (Running on oeis4.)