This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A069674 #10 Aug 06 2021 06:58:59 %S A069674 120,210,1035,2080,4095,4560,4950,5460,9045,13530,15400,17020,17205, %T A069674 17578,19306,20100,20503,20706,23005,30135,30628,36046,37401,40186, %U A069674 43071,43660,46360,46971,50721,51040,52003,53301,60031,63190,66430 %N A069674 Triangular numbers whose digit permutations yield at least two further triangular numbers. %e A069674 120 yields 21 and 210; 210 yields 21 and 120. %Y A069674 Cf. A000217, A077671, A095869, A095870. %K A069674 nonn,base %O A069674 1,1 %A A069674 _Amarnath Murthy_, Apr 06 2002 %E A069674 Edited, corrected and extended by _Ray Chandler_, Jun 29 2004 %E A069674 Offset changed to 1 by _Jinyuan Wang_, Aug 06 2021