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A273265
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Numbers k such that (16*10^k + 161)/3 is prime.
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0
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0, 1, 2, 3, 6, 7, 8, 10, 16, 17, 35, 53, 121, 155, 178, 487, 880, 1153, 2136, 2790, 2803, 5775, 5845, 5971, 7131, 13213, 13813, 17153, 31461, 38735, 93577, 188457
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OFFSET
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1,3
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COMMENTS
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For k>1, numbers n such that the digit 5 followed by k-2 occurrences of the digit 3 followed by the digits 87 is prime (see Example section).
a(33) > 2*10^5.
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LINKS
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EXAMPLE
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3 is in this sequence because (16*10^3 + 161)/3 = 5387 is prime.
Initial terms and primes associated:
a(1) = 0, 59;
a(2) = 1, 107;
a(3) = 2, 587;
a(4) = 3, 5387;
a(5) = 6, 5333387, etc.
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MATHEMATICA
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Select[Range[0, 100000], PrimeQ[(16*10^# + 161)/3] &]
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PROG
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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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