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A080218
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Monotonically increasing sequence such that every positive integer n appears if and only if d(n) doesn't (d(n)=number of divisors of n, A000005).
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3
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3, 5, 6, 7, 8, 10, 11, 13, 14, 15, 17, 19, 21, 22, 23, 26, 27, 29, 31, 33, 34, 35, 36, 37, 38, 39, 41, 43, 46, 47, 51, 53, 55, 57, 58, 59, 60, 61, 62, 65, 67, 69, 71, 72, 73, 74, 77, 79, 82, 83, 84, 85, 86, 87, 89, 90, 91, 93, 94, 95, 96, 97, 100, 101, 103, 106, 107, 108, 109
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OFFSET
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1,1
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REFERENCES
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M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards Applied Math. Series 55, 1964 (and various reprintings), p. 840.
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LINKS
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Table of n, a(n) for n=1..69.
M. Abramowitz and I. A. Stegun, eds., Handbook of Mathematical Functions, National Bureau of Standards, Applied Math. Series 55, Tenth Printing, 1972 [alternative scanned copy].
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EXAMPLE
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d(1)=1 and d(2)=2; therefore neither are included. Members include 3 (2 divisors), 6 (4 divisors) and 60 (12 divisors); other nonmembers include 4 (3 divisors), 12 (6 divisors) and 5040 (60 divisors).
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CROSSREFS
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Sequence in context: A163162 A181744 A160685 * A080651 A047330 A093511
Adjacent sequences: A080215 A080216 A080217 * A080219 A080220 A080221
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KEYWORD
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easy,nonn
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AUTHOR
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Matthew Vandermast, Mar 16 2003
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STATUS
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approved
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