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A112749
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Smallest prime of the form 5 followed by n copies of some k.
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1
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53, 577, 5333, 59999, 511111, 5111111111111, 59999999, 577777777, 5171717171717171717, 59999999999, 52727272727272727272727, 5111111111111, 53333333333333, 577777777777777, 5111111111111111
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OFFSET
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1,1
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LINKS
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EXAMPLE
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a(3) = 5333, 5 followed by three copies of 3.
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MAPLE
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cat3 := proc(a, b, n) local resu, i ; resu := a ; for i from 1 to n do resu := resu*10^( max(1, ilog10(b)+1) )+b ; od: RETURN(resu) ; end: A112749 := proc(n) local a, k; for k from 1 do a := cat3(5, k, n) ; if isprime(a) then RETURN(a) ; fi ; od: end: seq(A112749(n), n=1..20) ; # R. J. Mathar, Feb 08 2008
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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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