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A062685
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Smallest square with digit sum n (or 0 if no such square exists).
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3
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1, 0, 0, 4, 0, 0, 16, 0, 9, 64, 0, 0, 49, 0, 0, 169, 0, 576, 289, 0, 0, 1849, 0, 0, 4489, 0, 3969, 17956, 0, 0, 6889, 0, 0, 27889, 0, 69696, 98596, 0, 0, 97969, 0, 0, 499849, 0, 1887876, 698896, 0, 0, 2778889, 0, 0, 4999696, 0, 9696996, 19998784, 0, 0
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OFFSET
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1,4
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COMMENTS
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LINKS
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EXAMPLE
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16 is the smallest square with digit sum 7, so a(7)=16.
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MATHEMATICA
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Array[If[FreeQ[{1, 4, 7, 9}, FixedPoint[Total@ IntegerDigits@ # &, #]], 0, Block[{k = 1, s}, While[Total@ IntegerDigits@ Set[s, k^2] != #, k++]; s]] &, 57] (* Michael De Vlieger, Jul 06 2018 *)
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CROSSREFS
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KEYWORD
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base,nonn
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AUTHOR
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STATUS
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approved
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