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A078604
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Largest prime factor of the integer formed by truncating the decimal expansion of Pi to n places.
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3
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3, 31, 157, 349, 103, 314159, 392699, 8263, 7853, 9786893, 28954771, 157079632679, 68246533, 4304347, 67649047, 1002742628021, 1170899, 990371647, 14523877, 1186001, 1023100457, 451661057, 1492315939, 381315143078063, 950007203269
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OFFSET
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0,1
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LINKS
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FORMULA
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EXAMPLE
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a(3) = 157 since 314 = 2*157.
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MATHEMATICA
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f[n_] := FactorInteger[ IntegerPart[ Pi*10^(n - 1)]][[-1, 1]]; Array[f, 23] (* Robert G. Wilson v, May 30 2015 *)
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PROG
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(PARI) a(n) = vecmax(factor(floor(Pi*10^n))[, 1]); \\ Michel Marcus, Dec 28 2013
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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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