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A273944
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Numbers n such that (266*10^n-17)/3 is prime.
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0
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0, 1, 2, 3, 7, 8, 11, 14, 24, 29, 50, 78, 99, 192, 226, 519, 613, 651, 1492, 3720, 6567, 6791, 7226, 8471, 9050, 13521, 14255, 33529, 44072, 47844, 64102, 112930, 116024, 122872, 138328, 140681, 268407
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OFFSET
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1,3
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COMMENTS
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For n>1, numbers n such that the digits 88 followed by n-1 occurrences of the digit 6 followed by the digit 1 is prime (see Example section).
a(38) > 3*10^5.
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LINKS
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EXAMPLE
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3 is in this sequence because (266*10^3-17)/3 = 88661 is prime.
Initial terms and primes associated:
a(1) = 0, 83;
a(2) = 1, 881;
a(3) = 2, 8861;
a(4) = 3, 88661;
a(5) = 7, 886666661, etc.
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MATHEMATICA
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Select[Range[0, 100000], PrimeQ[(266*10^# - 17)/3] &]
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PROG
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(PARI) isok(n) = isprime((266*10^n - 17)/3); \\ Michel Marcus, Jun 18 2016
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CROSSREFS
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KEYWORD
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nonn,more
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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