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Search: id:A110786
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| A110786 |
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To obtain a(n), take the n-th palindrome P = A002113(n) and concatenate it with the smallest palindrome Q such that PQ is a prime. |
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+0
2
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| 11, 23, 31, 41, 53, 61, 71, 83, 97, 113, 223, 331, 443, 557, 661, 773, 881, 991, 1013, 1117, 1213, 1319, 14177, 1511, 1613, 171131, 1811, 1913, 2027, 2129, 2221, 232171, 2423, 2521, 2621, 2729, 28211, 2927, 3037, 3137, 32377, 3331, 3433, 3533
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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The palindrome 171 gives a prime 171131 when concatenated with 131 and no palindrome less than 131 gives a prime on concatenation: 1711,1713,1717,1719,17111, etc. up to 171121 are all composite.
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CROSSREFS
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Cf. A030675, A110787.
Sequence in context: A030665 A077501 A030675 this_sequence A059642 A090920 A126330
Adjacent sequences: A110783 A110784 A110785 this_sequence A110787 A110788 A110789
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KEYWORD
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base,easy,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Aug 12 2005
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EXTENSIONS
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More terms from Giovanni Resta (g.resta(AT)iit.cnr.it), Feb 08 2006
Edited by N. J. A. Sloane (njas(AT)research.att.com), Jan 16 2009
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