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A111434
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Numbers k such that the sums of the digits of k, k^2 and k^3 coincide.
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5
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0, 1, 10, 100, 468, 585, 1000, 4680, 5850, 5851, 5868, 10000, 28845, 46800, 58500, 58510, 58680, 58968, 100000, 288450, 468000, 585000, 585100, 586800, 589680, 1000000, 2884500, 4680000, 5850000, 5851000, 5868000, 5896800, 10000000
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OFFSET
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1,3
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COMMENTS
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The sequence is clearly infinite, since we can add trailing zeros. Is the subset of values not ending in 0 infinite too (see A114135)?
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LINKS
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EXAMPLE
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468 is in the sequence since 468^2 = 219024 and 468^3 = 102503232 and we have 18 = 4+6+8 = 2+1+9+0+2+4 = 1+0+2+5+0+3+2+3+2.
5851 is in the sequence because 5851, 34234201 (= 5851^2) and 200304310051 (=5851^3) all have digital sum 19.
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MAPLE
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s:=proc(n) local nn: nn:=convert(n, base, 10): sum(nn[j], j=1..nops(nn)): end: a:=proc(n) if s(n)=s(n^2) and s(n)=s(n^3) then n else fi end: seq(a(n), n=0..1000000); # Emeric Deutsch, May 13 2006
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MATHEMATICA
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SumOfDig[n_]:=Apply[Plus, IntegerDigits[n]]; Do[s=SumOfDig[n]; If[s==SumOfDig[n^2] && s==SumOfDig[n^3], Print[n]], {n, 10^6}]
Select[Range[0, 10000000], Length[Union[Total/@IntegerDigits[{#, #^2, #^3}]]] == 1&] (* Harvey P. Dale, Apr 26 2014 *)
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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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