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Search: id:A158725
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| A158725 |
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No repdigit composite numbers not divisible by 2, 3, 5 or 11. |
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+0
3
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| 49, 91, 119, 133, 161, 169, 203, 217, 221, 247, 259, 287, 289, 299, 301, 323, 329, 343, 361, 371, 377, 391, 403, 413, 427, 437, 469, 481, 493, 497, 511, 527, 529, 533, 551, 553, 559, 581, 589, 611, 623, 629, 637, 667, 679, 689, 697, 703, 707, 713, 721, 731
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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No repdigit composite numbers ending in 1, 3, 7 or 9, with digital root not a multiple of 3 and whose alternate digit sums either are not equal or do not differ by a multiple of 11.
The "compositeness" of larger entries of the sequence is not obvious right away or deducible by mere inspection, and hence readily lend themselves to be (erroneously) suspected as probable primes to the casual glance.
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CROSSREFS
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A007775, A053795, A008364
Sequence in context: A106311 A006832 A093894 this_sequence A090825 A157342 A118886
Adjacent sequences: A158722 A158723 A158724 this_sequence A158726 A158727 A158728
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KEYWORD
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nonn
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AUTHOR
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Lekraj Beedassy (blekraj(AT)yahoo.com), Mar 24 2009
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EXTENSIONS
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Corrected and extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Mar 27 2009
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