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A103195
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Concatenations of pairs of primes that differ by four.
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8
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37, 711, 1317, 1923, 3741, 4347, 6771, 7983, 97101, 103107, 109113, 127131, 163167, 193197, 223227, 229233, 277281, 307311, 313317, 349353, 379383, 397401, 439443, 457461, 463467, 487491, 499503, 613617, 643647, 673677, 739743, 757761, 769773
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OFFSET
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1,1
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LINKS
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FORMULA
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EXAMPLE
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The primes 3 and 7 differ by four, so the first term is 37.
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MATHEMATICA
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s = Select[ Prime[ Range[ 140]], PrimeQ[ # + 4] &]; FromDigits /@ Join @@@ IntegerDigits /@ Transpose[{s, s + 4}] (* Robert G. Wilson v, Mar 19 2005 *)
Join[{37}, FromDigits[Flatten[IntegerDigits/@#]]&/@Select[Partition[ Prime[ Range[ 200]], 2, 1], #[[2]]-#[[1]]==4&]] (* Harvey P. Dale, Sep 26 2016 *)
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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