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A058938
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Sum of first n digits of decimal expansion of pi is prime.
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1
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1, 6, 8, 13, 20, 21, 34, 36, 48, 56, 63, 87, 89, 92, 94, 104, 106, 107, 111, 116, 117, 118, 120, 130, 132, 133, 141, 146, 147, 162, 170, 173, 179, 183, 185, 186, 198, 202, 203, 206, 215, 217, 219, 220, 225, 242, 248, 249, 258, 264, 265, 270, 271, 285, 290, 291
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OFFSET
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1,2
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LINKS
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Table of n, a(n) for n=1..56.
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EXAMPLE
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a(2) = 6 because 3 + 1 + 4 + 1 + 5 + 9 = 23, which is prime.
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MAPLE
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Digits := 2000: it := evalf(Pi, 2000): for i from 1 to 2000 do a[i] := floor(it): it := 10*(it-floor(it)): od: s := 0: for i from 1 to 2000 do s := s+a[i]: if isprime(s) then printf(`%d, `, i) fi: od:
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MATHEMATICA
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a = First[ RealDigits[ N[ Pi, 300]]]; Do[ If[ PrimeQ[Plus @@ Take[a, n]], Print[n]], {n, 1, 300}]
Flatten[Position[Accumulate[RealDigits[\[Pi], 10, 500][[1]]], _?PrimeQ]] (* From Harvey P. Dale, Apr 03 2011 *)
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CROSSREFS
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Cf. A000796, A071117, A133213.
Sequence in context: A190546 A190558 A063188 * A101729 A209686 A178950
Adjacent sequences: A058935 A058936 A058937 * A058939 A058940 A058941
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KEYWORD
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easy,nonn,base
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AUTHOR
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G. L. Honaker, Jr., Jan 11 2001
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EXTENSIONS
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More terms from James A. Sellers, Jan 14 2001
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STATUS
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approved
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