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Numbers k such that the k-th triangular number contains only digits {2,3,5}.
2

%I #12 Mar 31 2023 02:28:21

%S 2,10,22,25,102,714,2114,2170,2550,21097,671302,258973177,1023088777,

%T 22460425354,211297574645,668630474213122229

%N Numbers k such that the k-th triangular number contains only digits {2,3,5}.

%H Giovanni Resta, <a href="http://www.numbersaplenty.com/tr/tr235.html">Tridigital Triangular Numbers</a>.

%Y Cf. A000217, A119152. See A119034 for a table of cross-references.

%K nonn,base,more

%O 1,1

%A _Giovanni Resta_, May 10 2006

%E a(16) from _Tyler Busby_, Mar 31 2023