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A068714
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Primes formed from a concatenation of 2 and 3^k for some k.
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2
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23, 29, 227, 281, 2243, 2729, 26561, 219683, 24782969, 210460353203, 2282429536481, 27625597484987, 250031545098999707, 279766443076872509863361, 2239299329230617529590083, 219383245667680019896796723, 2202755595904452569706561330872953769
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OFFSET
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0,1
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LINKS
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Table of n, a(n) for n=0..16.
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EXAMPLE
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2243 is a member as it is a concatenation of 2 and 243 = 3^5.
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MATHEMATICA
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Select[Table[FromDigits[Prepend[IntegerDigits[3^n], 2]], {n, 75}], PrimeQ] (* Jayanta Basu, May 22 2013 *)
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CROSSREFS
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Cf. A068712.
Sequence in context: A115396 A180538 A029541 * A036267 A107934 A155107
Adjacent sequences: A068711 A068712 A068713 * A068715 A068716 A068717
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KEYWORD
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nonn,base
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Mar 05 2002
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EXTENSIONS
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More terms from Sascha Kurz, Mar 17 2002
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STATUS
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approved
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