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A294722
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Numbers k such that (44^k - 1)/43 is prime.
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1
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OFFSET
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1,1
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COMMENTS
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The number corresponding to a(4) is a probable prime.
These are the indices of base-44 repunit primes, i.e., numbers k such that A002275(k) interpreted as a base-44 number and converted to decimal is prime. - Felix Fröhlich, Nov 08 2017
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LINKS
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MATHEMATICA
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ParallelMap[ If[ PrimeQ[(44^# - 1)/43], #, Nothing] &, Prime@Range @ 10000] (* Robert G. Wilson v, Nov 25 2017 *)
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PROG
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(PFGW) ABC2 (44^$a-1)/43 // -f{2*$a}
a: primes from 2 to 1000000
(PARI) is(n) = ispseudoprime((44^n-1)/43) \\ Felix Fröhlich, Nov 08 2017
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CROSSREFS
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Cf. A028491, A004061, A004062, A004063, A004023, A005808, A004064, A016054, A006032, A006033, A006034, A006035, A127995, A127996, A127997, A127998, A127999, A098438, A128002, A128003, A128004, A128005, A240765.
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KEYWORD
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nonn,more
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AUTHOR
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STATUS
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approved
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