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A007920
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Smallest number k such that n+k is prime.
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8
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2, 1, 0, 0, 1, 0, 1, 0, 3, 2, 1, 0, 1, 0, 3, 2, 1, 0, 1, 0, 3, 2, 1, 0, 5, 4, 3, 2, 1, 0, 1, 0, 5, 4, 3, 2, 1, 0, 3, 2, 1, 0, 1, 0, 3, 2, 1, 0, 5, 4, 3, 2, 1, 0, 5, 4, 3, 2, 1, 0, 1, 0, 5, 4, 3, 2, 1, 0, 3, 2, 1, 0, 1, 0, 5, 4, 3, 2, 1, 0, 3, 2, 1, 0, 5, 4, 3, 2, 1, 0, 7, 6, 5, 4, 3, 2, 1, 0, 3, 2, 1, 0, 1, 0, 3, 2, 1, 0, 1
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OFFSET
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0,1
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COMMENTS
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Smarandache complementary prime function.
a(n) = A007918(n) - n.
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REFERENCES
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M. Popescu, V. Seleacu, About the Smarandache Complementary Prime Function, Smarandache Notions Journal, Vol. 7, No. 1-2-3, 1996, 12-22.
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LINKS
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T. D. Noe, Table of n, a(n) for n = 0..10000
F. Smarandache, Only Problems, Not Solutions!.
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EXAMPLE
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a(1)=1 because 1+1=2=prime
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MATHEMATICA
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snk[n_]:=If[PrimeQ[n], 0, NextPrime[n]-n]; Array[snk, 110, 0] (* From Harvey P. Dale, Sep 19 2011 *)
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PROG
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(PARI) a(n)=nextprime(n)-n
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CROSSREFS
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Cf. A064722.
Sequence in context: A140728 A130068 A051699 * A127587 A175832 A082926
Adjacent sequences: A007917 A007918 A007919 * A007921 A007922 A007923
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KEYWORD
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nonn,easy
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AUTHOR
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R. Muller
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EXTENSIONS
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More terms from Joanna S. Bartlett (s1117611(AT)cedarville.edu)
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STATUS
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approved
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