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Search: id:A128278
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| A128278 |
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an=nth smallest integer m=p1*p2*p3, product of 3 odd primes such that d+2m/d are all primes for d dividing 2m. |
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2
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| 105, 165, 231, 935, 2109, 2795, 3021, 3819, 6981, 7205, 11285, 12341, 13101, 16419, 17549, 19839, 21749, 21995, 26391, 31229, 31269, 46631, 62651, 63645, 65391, 76155, 77585, 100955, 110811, 113555, 118031, 136451, 148359, 150245, 154679
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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E.g. 105=3.5.7, 2.3.5.7+1=211, 2+3.5.7=107, 3+2.5.7=73, 5+2.3.7=47, 7+2.3.5=37, 2.3+5.7=41, 2.5+3.7=31, 2.7+3.5=29 are all primes and 3.5.7 is the smallest such number, so a(1)=105.
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CROSSREFS
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Cf. A128276, A128277, A128279, A045536.
Adjacent sequences: A128275 A128276 A128277 this_sequence A128279 A128280 A128281
Sequence in context: A119434 A091495 A046405 this_sequence A128284 A046887 A026066
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KEYWORD
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nonn
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AUTHOR
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Kok Seng Chua (chuakokseng(AT)hotmail.com), Mar 05 2007
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