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A085597
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Numbers k such that k and k^3 use only odd digits.
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2
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1, 11, 15, 33, 39, 71, 91, 173, 175, 179, 335, 3337, 5597, 7353
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OFFSET
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1,2
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COMMENTS
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Numbers k such that k^3 uses only odd digits are in A030099.
No other terms below 10^16. The sequence is likely finite. - Max Alekseyev, Oct 17 2017
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LINKS
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EXAMPLE
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15 is a term because both 15 and 15^3=3375 use only odd digits.
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MATHEMATICA
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Select[Range[10000], And@@OddQ[Join[IntegerDigits[#], IntegerDigits[ #^3]]]&] (* Harvey P. Dale, May 15 2012 *)
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PROG
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(PARI) isoddd(n) = #select(x->((x%2) == 0), digits(n)) == 0;
isok(n) = isoddd(n) && isoddd(n^3); \\ Michel Marcus, Dec 03 2016
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CROSSREFS
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KEYWORD
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nonn,base,more
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AUTHOR
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STATUS
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approved
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