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A128398
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Numbers n such that n^2 divides 18^n-1.
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17
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OFFSET
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1,2
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COMMENTS
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17 divides a(n) for n>1. a(n) is a subset of A128358(n) = {1, 17, 289, 4913, 83521, 1419857, 5846759, ...} Numbers n such that n divides 18^n-1.
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LINKS
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Table of n, a(n) for n=1..3.
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MATHEMATICA
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a={}; Do[r=(18^n-1)/n^2; If[r==IntegerPart[r], AppendTo[a, n]], {n, 1, 10^3}]; a [From Vladimir Joseph Stephan Orlovsky, Aug 07 2008]
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CROSSREFS
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Cf. A128358 = numbers n such that n divides 18^n-1. Cf. A127103, A127104, A127105, A127106, A127107, A127102, A127101, A127100, A127092, A128405, A128393, A128394, A128395, A128396, A128397, A128398, A128399, A128400, A128401, A128402, A128403, A128404.
Sequence in context: A157255 A114432 A134686 * A210709 A187567 A160145
Adjacent sequences: A128395 A128396 A128397 * A128399 A128400 A128401
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KEYWORD
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bref,hard,more,nonn
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AUTHOR
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Alexander Adamchuk, Mar 08 2007
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STATUS
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approved
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