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A068121
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Smallest n-th power beginning with the concatenation of first n natural numbers.
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3
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OFFSET
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1,2
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COMMENTS
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B-file stops at a(25) because a(26) has 1107 digits. - Giovanni Resta, Jul 12 2016
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LINKS
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EXAMPLE
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12326391 = 231^3 is the smallest cube beginning with 123.
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MATHEMATICA
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a[n_] := Block[{t = Flatten@ Table[ IntegerDigits@i, {i, n}], m, v, h = 0}, m = Length@t; z = FromDigits@t; While[ Take[ IntegerDigits[(v = Ceiling[(z 10^h) ^ (1/n)])^n], m] != t, h++]; v^n]; Array[a, 25] (* Giovanni Resta, Jul 12 2016 *)
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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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EXTENSIONS
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STATUS
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approved
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