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Numbers k such that k and k^2 use only the digits 2, 3, 5, 6 and 9.
1

%I #10 Apr 12 2024 09:51:27

%S 3,5,6,23,25,63,235,236,256,2323,2365,2523,22925,23566,25565,26335,

%T 59635,62925,232236,236565,252236,255663,263235,626335,996963,2293325,

%U 2353656,2359923,2555256,2556663,2556665,2633235,2639236,5996963,6263335,6295236,9626335,9626366,9639635,9966925,9996963,22955665,23522235,23566925,23592235

%N Numbers k such that k and k^2 use only the digits 2, 3, 5, 6 and 9.

%C Generated with DrScheme.

%H Jonathan Wellons, <a href="/A137082/b137082.txt">Table of n, a(n) for n = 1..388</a>

%H J. Wellons, <a href="https://web.archive.org/web/20090206165028/http://jonathanwellons.com/shared-digits/">Tables of Shared Digits</a> [archived]

%e 596365936252535^2 = 355652329922362639359293926225.

%t nsnQ[n_]:=SubsetQ[{2,3,5,6,9},IntegerDigits[n^2]]; Table[Select[ FromDigits/@ Tuples[{2,3,5,6,9},n],nsnQ],{n,8}]//Flatten (* _Harvey P. Dale_, Jun 24 2018 *)

%K base,nonn

%O 1,1

%A Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008