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 A137078 Numbers n such that n and the square of n use only the digits 2, 3, 4 and 9. 0
 2, 3, 4943, 499423, 49993443, 4999932923, 499999999293429243923, 499999999999293429243923 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Generated with DrScheme LINKS J. Wellons, Tables of Shared Digits [BROKEN LINK] EXAMPLE 4999932923^2 = 24999329234499323929 MAPLE g:= n -> convert(convert(n, base, 10), set) subset {2, 3, 4, 9}: Res:= 2, 3: extend:= proc(n, d) local B; global Res; B:= {seq(x*10^d+n, x=[2, 3, 4, 9])}; Res:= Res, op(select(t -> g(t^2), B)); op(select(t -> g(t^2 mod 10^(d+1)), B)) end proc: Agenda:= {2, 3, 4, 9}: for d from 1 to 25 do Agenda:= map(extend, Agenda, d) od: sort([Res]); # Robert Israel, Oct 29 2018 CROSSREFS Cf. A136809. Sequence in context: A271631 A068826 A085944 * A146026 A115640 A212494 Adjacent sequences:  A137075 A137076 A137077 * A137079 A137080 A137081 KEYWORD base,nonn AUTHOR Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008 EXTENSIONS a(7)-a(8) from Andrew Howroyd, Oct 24 2018 STATUS approved

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Last modified February 17 18:46 EST 2019. Contains 320222 sequences. (Running on oeis4.)