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Search: id:A070219
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| A070219 |
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Smallest prime obtained as a concatenation of n and a number m greater than n. |
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+0
4
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| 13, 23, 37, 47, 59, 67, 79, 89, 911, 1013, 1117, 1213, 1319, 1423, 1523, 1619, 1721, 1823, 1931, 2027, 2129, 2237, 2333, 2437, 2531, 2633, 2729, 2833, 2939, 3037, 3137, 3251, 3343, 3449, 3539, 3637, 3739, 3847, 3943, 4049, 4153, 4243, 4349, 4447, 4547
(list; graph; listen)
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OFFSET
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1,1
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COMMENT
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If we change the definition to m >= n, then a(1) becomes 11, but nothing else changes.
Conjectures: There is at least one number k with n<k<2n such that the concatenation n and n+k is a prime. For all m there is at least one number k with m*n < k < (m+1)*n such that the concatenation n and n+k is a prime.
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CROSSREFS
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Cf. A089713, A089715.
Sequence in context: A089777 A050857 A089714 this_sequence A046119 A164408 A164416
Adjacent sequences: A070216 A070217 A070218 this_sequence A070220 A070221 A070222
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KEYWORD
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base,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Nov 17 2003
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EXTENSIONS
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Edited by David Wasserman (wasserma(AT)spawar.navy.mil), Feb 05 2004
Further edited by N. J. A. Sloane (njas(AT)research.att.com), Oct 21 2008 at the suggestion of R. J. Mathar
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