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A271640
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Numbers k such that 3*10^k + 73 is prime.
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0
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1, 2, 5, 6, 13, 37, 50, 55, 71, 89, 217, 352, 355, 398, 449, 668, 742, 870, 1360, 1579, 2848, 3774, 5039, 5051, 6134, 6824, 7255, 12586, 17106, 27502, 30581, 33817, 97399, 170800, 172219, 177872
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OFFSET
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1,2
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COMMENTS
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For k > 1, numbers k such that the digit 3 followed by k-2 occurrences of the digit 0 followed by the digits 73 is prime (see Example section).
a(37) > 2*10^5.
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LINKS
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EXAMPLE
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5 is in this sequence because 3*10^5 + 73 = 300073 is prime.
Initial terms and associated primes:
a(1) = 1, 103;
a(2) = 2, 373;
a(3) = 5, 300073;
a(4) = 6, 3000073;
a(5) = 13, 30000000000073, etc.
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MATHEMATICA
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Select[Range[0, 100000], PrimeQ[3*10^# + 73] &]
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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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