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A210506
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Numbers k such that (11^k - 2^k)/9 is prime.
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10
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2, 5, 11, 13, 331, 599, 18839, 23747, 24371, 29339, 32141, 67421
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OFFSET
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1,1
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COMMENTS
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All terms are prime.
a(13) > 10^5.
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LINKS
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MATHEMATICA
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Select[ Prime[ Range[1, 100000] ], PrimeQ[ (11^# - 2^#)/9 ]& ]
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PROG
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CROSSREFS
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Cf. A004063, A028491, A057468, A059801, A121877, A128024, A128025, A128026, A128027, A128028, A128029, A128030, A128031, A128032.
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KEYWORD
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hard,more,nonn
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AUTHOR
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STATUS
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approved
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