%I #10 May 10 2025 16:16:34

%S 1,3,6,12,19,21,28,36,51,54,55,63,66,82,87,91,99,102,109,132,147,153,

%T 165,168,171,208,252,307,309,351,352,379,381,417,423,451,501,505,507,

%U 523,534,564,577,582,591,594,595,604,613,627,631,645,649,654,666,672,694,753,766,771

%N Triangular numbers written backwards and sorted, duplicates removed.

%e 109 is a member because 90100 is a triangular number. - _Sean A. Irvine_, Feb 01 2025

%Y Cf. A004158.

%K base,nonn

%O 1,2

%A _Jason Earls_, Sep 14 2002

%E Missing terms inserted by _Sean A. Irvine_, Feb 01 2025