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A125197
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Numbers such that pre- and post-concatenating 7, 13 and 31 results in six primes.
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0
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19, 3583, 11287, 62989, 63409, 89491, 93187, 104107, 106783, 155851, 178351, 1082467, 1219399, 1510207, 1566613, 1581469, 2246173, 2920693, 3081499, 3342277, 3523339, 3781849, 3820543, 4010161, 4824163, 4865827, 6091597
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| It is conjectured that 7, 13 and 31 is the only triplet with this property
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EXAMPLE
| 3583 is a member as 3583, 73583, 35837, 123583, 358313, 313583, 358331 are all prime.
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CROSSREFS
| Sequence in context: A055415 A196541 A195756 * A099809 A145214 A172662
Adjacent sequences: A125194 A125195 A125196 * A125198 A125199 A125200
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KEYWORD
| hard,nonn,base
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AUTHOR
| Anton Vrba (antonvrba(AT)yahoo.com), Jan 13 2007
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