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A099019
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Odd composite numbers n such that n-2 and n+2 are also composite.
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0
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93, 117, 119, 121, 123, 143, 145, 185, 187, 203, 205, 207, 215, 217, 219, 245, 247, 287, 289, 297, 299, 301, 303, 321, 323, 325, 327, 341, 343, 363, 393, 405, 413, 415, 425, 427, 453, 471, 473, 475, 483, 495, 513, 515, 517, 527, 529, 531, 533, 535, 537, 551
(list; graph; refs; listen; history; internal format)
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OFFSET
| 0,1
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COMMENTS
| Not a difference of two primes. - Juri-Stepan Gerasimov (2stepan(AT)rambler.ru), Oct 10 2009
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EXAMPLE
| 93 is the first term because 91=7*13, 93=3*31 and 95=5*19 are all composite and there is no smaller odd composite with both odd neighbors composite.
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PROG
| (PARI) forstep(n=9, 1000, 2, if(!isprime(n)&&!isprime(n-2)&&!isprime(n+2), print1(n, ", ")))
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CROSSREFS
| Sequence in context: A020320 A039550 A167776 * A082131 A153684 A048257
Adjacent sequences: A099016 A099017 A099018 * A099020 A099021 A099022
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KEYWORD
| nonn
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AUTHOR
| Rick L. Shepherd (rshepherd2(AT)hotmail.com), Nov 13 2004
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