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A144246
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Prime numbers of the form 10^k +- 9.
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2
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19, 109, 991, 1009, 10009, 99991, 9999991, 1000000009, 1000000000000000009, 10000000000000000000009, 999999999999999999999999999999991, 999999999999999999999999999999999999999999991
(list;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,1
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COMMENTS
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This sequence illustrates the base-n representation of numbers having the form n^k +- (n - 1).
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LINKS
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Table of n, a(n) for n=1..12.
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MATHEMATICA
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Select[Sort[Flatten[Table[10^n+{9, -9}, {n, 50}]]], PrimeQ] (* Harvey P. Dale, Jul 22 2016 *)
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CROSSREFS
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Cf. A000040, A000668, A144231, A144232, A144233, A144234, A144236, A144242, A144245
Sequence in context: A280628 A191566 A118607 * A281170 A158715 A186105
Adjacent sequences: A144243 A144244 A144245 * A144247 A144248 A144249
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KEYWORD
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nonn
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AUTHOR
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Reikku Kulon, Sep 15 2008
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STATUS
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approved
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