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A068659
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Primes formed from the concatenation of n, n-1 and n for some n > 0.
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3
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101, 131213, 171617, 313031, 333233, 434243, 474647, 494849, 636263, 777677, 898889, 939293, 117116117, 119118119, 127126127, 133132133, 151150151, 159158159, 161160161, 163162163, 199198199, 243242243, 269268269, 273272273, 277276277
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OFFSET
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1,1
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LINKS
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MAPLE
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for n from 1 to 1000 do a := n+10^( floor(log(n)/log(10)+0.000001 )+1)*(n-1); a := a+10^( floor(log(a)/log(10)+0.000001 )+1)*n; b[n] := a:end do:k := 0:for n from 2 to 1000 doif(isprime(b[n])) then k := k+1:c[k] := b[n]:end if:end do:seq(c[j], j=1..k);
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MATHEMATICA
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A068659={}; Do[t=FromDigits[Flatten[IntegerDigits/@{(n+1), n, (n+1)}]]; If[PrimeQ[t], AppendTo[A, t]], {n, 500}]; A068659 (* K. D. Bajpai, Jul 03 2014 *)
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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