%I #15 Mar 30 2023 05:18:27
%S 6,66,666,68898988866,88698868996686886,696999969866686966889999889666
%N Triangular numbers composed of digits {6,8,9}.
%C a(7) > 10^37. - _Max Alekseyev_, Apr 30 2010
%C a(7) > 10^40. - _Tyler Busby_, Mar 29 2023
%H Giovanni Resta, <a href="http://www.numbersaplenty.com/tr/tr689.html">Tridigital Triangular Numbers</a>.
%F a(n) = A000217(A119235(n)). - _Michel Marcus_, Mar 27 2023
%Y Cf. A000217, A053975, A119235. See A119033 for a table of cross-references.
%K nonn,base,more
%O 1,1
%A _Giovanni Resta_, May 10 2006
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