|
%I #9 Apr 12 2024 09:51:27
%S 1,5,11,15,27,77,227,527,715,1515,1711,2777,7227,7715,22715,52915,
%T 71911,97527,159911,275527,277977,715511,727511,977511,2791515,
%U 7219777,7557511,7715515,7727711,7727715,9591515,9777515,9797511,9797715,9955511,11292915,12292915,17255515,27771527,27797715,27797977,27915515,71971911,72299211
%N Numbers k such that k and k^2 use only the digits 1, 2, 5, 7 and 9.
%C Generated with DrScheme.
%H Jonathan Wellons, <a href="/A137009/b137009.txt">Table of n, a(n) for n = 1..272</a>
%H J. Wellons, <a href="https://web.archive.org/web/20090206165028/http://jonathanwellons.com/shared-digits/">Tables of Shared Digits</a> [archived]
%e 759722171291527^2 = 577177777551912291775221991729.
%t With[{c={1,2,5,7,9}},Select[Flatten[Table[FromDigits/@Tuples[c,n],{n,8}]],SubsetQ[ c,IntegerDigits[#^2]]&]] (* _Harvey P. Dale_, Oct 14 2020 *)
%K base,nonn,changed
%O 1,2
%A Jonathan Wellons (wellons(AT)gmail.com), Jan 22 2008
|
