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 A054031 Numbers whose square contains exactly 3 distinct digits. 10
 13, 14, 16, 17, 18, 19, 23, 24, 25, 27, 28, 29, 31, 34, 35, 39, 40, 41, 45, 46, 47, 50, 56, 58, 60, 62, 63, 65, 67, 68, 70, 75, 76, 77, 80, 81, 83, 85, 90, 91, 92, 94, 97, 101, 102, 107, 108, 110, 111, 119, 120, 121, 122, 129, 131, 141, 149, 150, 162, 165 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 LINKS Giovanni Resta, Table of n, a(n) for n = 1..12299 (terms < 10^18, first 1000 terms from T. D. Noe) Michael Geißer, Theresa Körner, Sascha Kurz, and Anne Zahn, Squares with three digits Carlos Rivera, Puzzle 313. Squares having only k distinct digits, The Prime Puzzles and Problems Connection. FORMULA A235718(n) = a(n)^2. - Giovanni Resta, Apr 28 2017 MAPLE f := []; for i from 0 to 200 do if nops({op(convert(i^2, base, 10))})=3 then f := [op(f), i] fi; od; f; MATHEMATICA t = {}; n = -1; While[Length[t] < 50, n++; If[Length[Union[IntegerDigits[n^2]]] == 3, AppendTo[t, n]]] (* T. D. Noe, Apr 26 2013 *) Select[Range[200], Length[Union[IntegerDigits[#^2]]]==3&] (* Harvey P. Dale, Aug 17 2014 *) PROG (PARI) is(n)=#Set(digits(n^2))==3 \\ Charles R Greathouse IV, Feb 11 2017 CROSSREFS Cf. A235718, A016069, A054032, A054033, A054034, A054035, A054036, A054037, A054038, A054039. Sequence in context: A048037 A346657 A171492 * A060275 A083984 A272022 Adjacent sequences: A054028 A054029 A054030 * A054032 A054033 A054034 KEYWORD nonn,base AUTHOR Asher Auel (asher.auel(AT)reed.edu), Feb 29 2000 STATUS approved

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Last modified March 21 13:27 EDT 2023. Contains 361402 sequences. (Running on oeis4.)