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A188486
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Numbers n such that abundance(n) is an odd square.
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3
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550564, 15038884, 57365476, 197686728, 257859364, 1027291978962, 4644774970276, 319916794343524, 694453849937352, 97695446432293264, 359108743507594276
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OFFSET
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1,1
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COMMENTS
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Counterexamples to the Kravitz conjecture. Subsequence of A188484 with positive abundances. Abundances are A188488, sigma(n) - 2n.
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LINKS
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Table of n, a(n) for n=1..11.
Eric Weisstein's World of Mathematics, Kravitz Conjecture
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CROSSREFS
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Cf. A188484, A188488.
Sequence in context: A184568 A218098 A077456 * A204571 A196511 A196733
Adjacent sequences: A188483 A188484 A188485 * A188487 A188488 A188489
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KEYWORD
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nonn,hard,changed
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AUTHOR
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Eric W. Weisstein, Apr 01 2011
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EXTENSIONS
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a(4), a(5) from D. S. McNeil, Apr 02 2011
a(6) - a(8) from Jack Brennen, May 03 2011
a(9) from Jack Brennen and Charles R Greathouse IV, May 04 2011
a(10)-a(11) from Charles R Greathouse IV, May 04, 2011
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STATUS
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approved
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