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Search: id:A161945
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| A161945 |
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Numbers n with property that three consequtive odd numbers {n,n+2,n+4} are all composite. |
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1
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| 91, 115, 117, 119, 121, 141, 143, 183, 185, 201, 203, 205, 213, 215, 217, 243, 245, 285, 287, 295, 297, 299, 301, 319, 321, 323, 325, 339, 341, 361, 391, 403, 411, 413, 423, 425, 451, 469, 471, 473, 481, 493, 511, 513, 515, 525, 527, 529, 531, 533, 535, 549
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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143 is in the sequence because 143=11*13, 145=5*29, 147=3*49. [From Emeric Deutsch (deutsch(AT)duke.poly.edu), Jun 27 2009]
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MAPLE
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a := proc (n) if isprime(2*n-1) = false and isprime(2*n+1) = false and isprime(2*n+3) = false then 2*n-1 else end if end proc: seq(a(n), n = 2 .. 300); [From Emeric Deutsch (deutsch(AT)duke.poly.edu), Jun 27 2009]
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CROSSREFS
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Sequence in context: A020318 A126134 A020223 this_sequence A140389 A157345 A092125
Adjacent sequences: A161942 A161943 A161944 this_sequence A161946 A161947 A161948
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KEYWORD
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nonn
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AUTHOR
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Zak Seidov (zakseidov(AT)yahoo.com), Jun 22 2009
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