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A111391
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Numbers k such that 11*10^k - 1 is prime.
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2
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1, 9, 11, 17, 22, 29, 36, 37, 52, 166, 448, 2011, 3489, 4871, 6982, 10024, 16974, 33287, 47364, 58873, 126160, 234424, 382881, 524706
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OFFSET
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1,2
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COMMENTS
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Numbers k such that 10^(k+1) + (10^k-1) is a prime.
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LINKS
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MATHEMATICA
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Do[ If[ PrimeQ[10^(n + 1) + (10^n - 1)], Print[n]], {n, 9500}]
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PROG
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CROSSREFS
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KEYWORD
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more,nonn
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AUTHOR
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EXTENSIONS
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a(20)-a(21) from P. Kurtovic submitted by Ray Chandler, Sep 17 2013
a(22)-a(24) from Kamada data by Tyler Busby, Apr 14 2024
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STATUS
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approved
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