%I #8 Aug 11 2024 14:41:33

%S 9,98989978877879888789778997998889

%N Squares composed of digits {7,8,9}.

%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#789">Sporadic tridigital solutions</a>

%F a(n) = A058471(n)^2.

%Y Cf. A058471.

%K nonn,base,hard,more,bref

%O 1,1

%A _Patrick De Geest_, Nov 15 2000