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A089294
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Smallest prime p_k such that n can be written as a "plus-minus" sum n=sum_(i=1..k)e_i*(p_i)^2 with distinct primes p_i<=p_k, where e_i is 1 or -1.
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3
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19, 13, 19, 13, 2, 3, 13, 19, 13, 3, 13, 7, 5, 3, 13, 7, 5, 13, 13, 7, 5, 5, 13, 13, 7, 5, 13, 13, 7, 5, 5, 13, 13, 7, 5, 13, 7, 7, 5, 13, 7, 17, 11, 11, 7, 7, 17, 11, 13, 7, 17, 11, 11, 7, 7, 17, 11, 13, 7, 11, 11, 7, 7, 11, 13, 7, 17, 11, 11, 7, 7, 17, 11, 13, 7, 17, 11, 11, 7, 7, 17, 11
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OFFSET
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0,1
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COMMENTS
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The first terms where this sequence differs from A088934 are n=22,31,52,87,89,98,118,127,...
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LINKS
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EXAMPLE
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a(22)=13 because 22 can be represented as -13^2+11^2+7^2+5^2-2^2.
The corresponding representation with the minimum number of terms is
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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