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A067552
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a(n) = SumOfDigits(n)^2 - SumOfDigits(n^2), where SumOfDigits = A007953.
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5
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0, 0, 0, 0, 9, 18, 27, 36, 54, 72, 0, 0, 0, 0, 9, 27, 36, 45, 72, 90, 0, 0, 0, 9, 18, 36, 45, 63, 81, 108, 0, 0, 18, 18, 36, 54, 63, 81, 108, 135, 9, 9, 18, 27, 45, 72, 90, 108, 135, 162, 18, 27, 36, 45, 63, 90, 108, 126, 153, 180, 27, 36, 45, 54, 81, 108, 126, 144, 180, 207
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OFFSET
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0,5
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COMMENTS
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LINKS
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FORMULA
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EXAMPLE
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a(16) = SumOfDigits(16)^2 - SumOfDigits(16^2) = (1+6)^2 - SumOfDigits(256) = 7^2 - (2+5+6) = 49 - 13 = 36.
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MATHEMATICA
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f[n_] := Plus @@ IntegerDigits[n]^2 - Plus @@ (IntegerDigits[n^2]); Table[ f[n], {n, 0, 100}]
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PROG
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(PARI) a(n) = sumdigits(n)^2 - sumdigits(n^2); \\ Michel Marcus, Sep 01 2016
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CROSSREFS
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KEYWORD
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nonn,base
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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