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A103534
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Concatenations of pairs of primes that differ by 1000.
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3
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131013, 191019, 311031, 611061, 971097, 1031103, 1091109, 1511151, 1631163, 1811181, 1931193, 2231223, 2291229, 2771277, 2831283, 3071307, 3671367, 3731373, 4091409, 4331433, 4391439, 4871487, 4991499, 5231523, 5711571
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OFFSET
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1,1
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COMMENTS
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All terms are multiples of 3.
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LINKS
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FORMULA
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a(n) = Concatenate(P, P+1000) iff P prime and P+1000 prime.
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EXAMPLE
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1811181 is in this sequence because 181 is prime, 181+1000 = 1181 is prime and those two primes are concatenated.
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MATHEMATICA
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10001#+1000&/@Select[Prime[Range[150]], PrimeQ[#+1000]&] (* Harvey P. Dale, Sep 01 2017 *)
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CROSSREFS
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KEYWORD
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base,easy,nonn
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AUTHOR
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STATUS
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approved
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