%I A069790
%S A069790 1,120,210,300,112101,100600020,101111310,110120220,200130021,
%T A069790 200310120,1000051003,1010004040,1130002030,1411000003,2002021003,
%U A069790 3200200003,5000050000,100110002070,111111101310,111202101003
%N A069790 Triangular numbers with arithmetic mean of digits = 1 (sum of digits 
               = number of digits).
%C A069790 The sum of the digits of a triangular number is 0, 1, 3 or 6 (mod 9).
%t A069790 s=Select[Range[500000], Length[z=IntegerDigits[ #(#+1)/2]]==Plus@@z&]; 
               s(s+1)/2
%Y A069790 Sequence in context: A054572 A056994 A114823 this_sequence A064224 A069674 
               A003015
%Y A069790 Adjacent sequences: A069787 A069788 A069789 this_sequence A069791 A069792 
               A069793
%K A069790 base,nonn
%O A069790 1,2
%A A069790 Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Apr 08 2002
%E A069790 Edited by Dean Hickerson (dean.hickerson(AT)yahoo.com) and Robert G. 
               Wilson v (rgwv(AT)rgwv.com), Apr 10 2002