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A268146
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Twin prime pairs concatenated to their average in decimal representation (the greater twin prepended, the lesser appended).
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0
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543, 765, 131211, 191817, 313029, 434241, 616059, 737271, 103102101, 109108107, 139138137, 151150149, 181180179, 193192191, 199198197, 229228227, 241240239, 271270269, 283282281, 313312311, 349348347, 421420419, 433432431, 463462461, 523522521, 571570569, 601600599
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OFFSET
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1,1
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COMMENTS
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The greater prime of a twin prime pair is prepended and the lesser one is appended to their average (nonprime, interprime).
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LINKS
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EXAMPLE
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a(1)=543: the greater prime {5} of the first twin prime pair {3, 5} is prepended and the lesser prime {3} is appended to their average {4}.
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MATHEMATICA
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UpToN[k_]:=FromDigits//@ StringJoin//@ ToString/@ {#+1, #, #-1} &/@ Select[ Table[ Prime[n]+1, {n, 2, PrimePi[k]}], PrimeQ[#+1] &]; UpToN[10000]
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CROSSREFS
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KEYWORD
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nonn,base,easy
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AUTHOR
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STATUS
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approved
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