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Search: id:A140775
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| A140775 |
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A number n is included if p + n/p is prime for every prime p that divides n. |
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+0
3
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| 2, 6, 10, 22, 30, 34, 42, 58, 70, 78, 82, 102, 118, 130, 142, 190, 202, 210, 214, 274, 298, 310, 322, 330, 358, 382, 394, 442, 454, 462, 478, 510, 538, 562, 582, 610, 622, 658, 694, 714, 730, 742, 790, 838, 862, 922, 930, 970, 1002, 1038, 1042, 1110, 1138, 1198
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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All terms of this sequence are even and squarefree.
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EXAMPLE
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The primes dividing 70 are 2, 5, 7. Now, 2 + 70/2 = 37; 5 + 70/5 = 19; 7 + 70/7 = 17. Since 37, 19, and 17 are each prime, then 70 is included in this sequence.
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MATHEMATICA
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fQ[n_] := Block[{p = First@ Transpose@ FactorInteger@ n}, Union@ PrimeQ[p + n/p] == {True}]; Select[ Range[2, 1221], fQ@# &] - Robert G. Wilson v, (rgwv(AT)rgwv.com), May 30 2008
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CROSSREFS
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Cf. A140776, A140777.
Adjacent sequences: A140772 A140773 A140774 this_sequence A140776 A140777 A140778
Sequence in context: A103628 A034450 A112861 this_sequence A077064 A080715 A034168
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KEYWORD
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nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), May 29 2008
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EXTENSIONS
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More terms from Robert G. Wilson v, (rgwv(AT)rgwv.com), May 30 2008
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