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Search: id:A152758
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| A152758 |
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Numbers whose deficiency plus the number of proper divisors is not a prime number (See A152864). |
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+0
2
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| 1, 8, 12, 15, 24, 25, 30, 32, 33, 35, 36, 39, 40, 42, 44, 48, 50, 51, 54, 56, 60, 63, 65, 66, 68, 69, 72, 78, 80, 81, 84, 85, 87, 90, 92, 96, 98, 100, 102, 105, 108, 112, 114, 116, 117, 120, 121, 123, 126, 128, 129, 130, 132, 136, 138, 140, 141, 143, 144, 148, 150, 153
(list; graph; listen)
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OFFSET
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1,2
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MAPLE
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with(numtheory): a := proc (n) if isprime(2*n-sigma(n)+tau(n)-1) = false then n else end if end proc: seq(a(n), n = 1 .. 200); [From Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 08 2009]
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CROSSREFS
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Cf. A000005, A000040, A000203, A032741, A033879, A152757, A152770, A152864.
Sequence in context: A033949 A062373 A031034 this_sequence A160258 A071280 A033942
Adjacent sequences: A152755 A152756 A152757 this_sequence A152759 A152760 A152761
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KEYWORD
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easy,nonn
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AUTHOR
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Omar E. Pol (info(AT)polprimos.com), Dec 14 2008
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EXTENSIONS
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Extended by Emeric Deutsch (deutsch(AT)duke.poly.edu), Jan 08 2009
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