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 A137079 Numbers k such that k and k^2 use only the digits 2, 3, 5 and 6. 1
 5, 6, 25, 235, 256, 23566, 2352365325, 23523653335 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS Generated with DrScheme. No more terms < 10^26. - Robert Israel, Nov 24 2023 LINKS Table of n, a(n) for n=1..8. Jonathan Wellons, Tables of Shared Digits [archived] EXAMPLE 2352365325^2 = 5533622622262355625. MAPLE Good := {2, 3, 5, 6}: R:= 5, 6: G[1]:= {5, 6}: for d from 2 to 26 do G[d]:= select(t -> member(floor((t^2 mod 10^d)/10^(d-1)), Good), map(t -> seq(10^(d-1)*i+t, i=Good), G[d-1])); for t in G[d] do if convert(convert(t^2, base, 10), set) subset Good then R:= R, t fi od od: sort([R]); # Robert Israel, Nov 24 2023 MATHEMATICA fQ[n_] := Block[{d = DigitCount@ n}, Total@ Delete[d, {{2}, {3}, {5}, {6}}] == 0]; Select[Range@ 100000, fQ@ # && fQ[#^2] &] (* Michael De Vlieger, Apr 29 2015 *) PROG (Python) from itertools import product A137079_list = [int(''.join(a)+b) for l in range(10) for a in product('2356', repeat = l) for b in ('5', '6') if set(str(int(''.join(a)+b)**2)) <= {'2', '3', '5', '6'}] # Chai Wah Wu, Apr 29 2015 CROSSREFS Sequence in context: A003226 A088834 A137081 * A163658 A121180 A022165 Adjacent sequences: A137076 A137077 A137078 * A137080 A137081 A137082 KEYWORD base,nonn,more AUTHOR Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008 STATUS approved

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Last modified August 3 08:07 EDT 2024. Contains 374885 sequences. (Running on oeis4.)