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A136910 Numbers k such that k and k^2 use only the digits 0, 2 and 5. 1

%I #9 Apr 12 2024 09:51:26

%S 0,5,50,500,505,5000,5005,5050,50000,50005,50050,50500,500000,500005,

%T 500050,500500,500505,505000,5000000,5000005,5000050,5000500,5000505,

%U 5005000,5005050,5050000,5050005,50000000,50000005,50000050,50000500,50000505,50005000,50005005,50005050,50050000,50050500,50500000,50500005,50500050,500000000

%N Numbers k such that k and k^2 use only the digits 0, 2 and 5.

%C Generated with DrScheme.

%H Jonathan Wellons, <a href="/A136910/b136910.txt">Table of n, a(n) for n = 1..446</a>

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

%e 505000500500005^2 = 255025505505255550255005000025.

%t Select[FromDigits/@Tuples[{0,2,5},9],SubsetQ[{0,2,5},IntegerDigits[ #^2]]&] (* _Harvey P. Dale_, May 30 2019 *)

%K base,nonn

%O 1,2

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

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Last modified June 18 22:34 EDT 2024. Contains 373487 sequences. (Running on oeis4.)