%I #7 Mar 30 2012 17:27:18
%S 0,1,4,5,6,10,15,16,17,18,21,22,23,24,25,28,36,45,55,56,57,66,78,91,
%T 105,120,121,122,136,137,138,139,140,141,142,143,153,154,155,156,157,
%U 158,159,160,161,171,172,173,174,175,176,177,178,179,180,190,210,231
%N a(n) is taken to be the smallest positive integer greater than a(n-1) which is consistent with the condition "n is a member of the sequence if and only if a(n) is a triangular number".
%H B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="http://www.cs.uwaterloo.ca/journals/JIS/index.html">Numerical analogues of Aronson's sequence</a>, J. Integer Seqs., Vol. 6 (2003), #03.2.2.
%H B. Cloitre, N. J. A. Sloane and M. J. Vandermast, <a href="http://arXiv.org/abs/math.NT/0305308">Numerical analogues of Aronson's sequence</a> (math.NT/0305308)
%Y See A079000, A079253, A079254, A079256, A079258 for similar sequences.
%K nonn,easy
%O 0,3
%A _N. J. A. Sloane_ and _Matthew Vandermast_, Feb 04 2003