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%I #7 Aug 11 2024 14:41:33
%S 2,88,88002411582,47146022358675418
%N Numbers k such that k^2 contains only digits {2,4,7}.
%H P. De Geest, <a href="https://www.worldofnumbers.com/threedigits.htm">Index to related sequences</a>
%H Hisanori Mishima, <a href="http://www.asahi-net.or.jp/~KC2H-MSM/mathland/math02/math0210.htm#247">Sporadic tridigital solutions</a>
%Y Cf. A058460.
%K nonn,base,hard,more
%O 1,1
%A _Patrick De Geest_, Nov 15 2000