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A213721
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Smallest prime that is the sum of four nonzero squares in exactly n ways.
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2
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2, 7, 31, 67, 97, 103, 157, 199, 277, 223, 307, 383, 439, 367, 547, 463, 673, 613, 577, 751, 643, 733, 787, 727, 853, 983, 997, 967, 1171, 1223, 1063, 1087, 1123, 1613, 1237, 1279, 1471, 1453, 1669, 1423, 1483, 1597, 1627, 1543, 1567, 1747, 2039, 1753, 1867, 1951
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OFFSET
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0,1
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LINKS
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EXAMPLE
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a(2) = 31 because 31 = 2*1 + 4 + 25 = 4 + 3*9.
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MATHEMATICA
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lst = {}; Do[p = 2; While[True, If[PrimeQ[p] && Length@Select[PowersRepresentations[p, 4, 2], ! MemberQ[#, 0] &] == n, AppendTo[lst, p]; Break[]]; p++], {n, 0, 49}]; lst
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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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