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 A095869 #8 Aug 06 2021 07:06:20 %S A095869 1,3,6,15,21,28,36,45,55,66,78,91,136,171,231,276,378,406,435,465,528, %T A095869 561,595,666,703,741,861,903,990,1081,1128,1176,1225,1275,1326,1431, %U A095869 1540,1596,1653,1711,1770,1953,2016,2211,2278,2346,2485,2556,2628,2775 %N A095869 Triangular numbers whose digit permutations yield no further triangular numbers. %Y A095869 Cf. A000217, A069674, A077671, A095870. %K A095869 nonn,base %O A095869 1,2 %A A095869 _Ray Chandler_, Jun 29 2004 %E A095869 Offset changed to 1 by _Jinyuan Wang_, Aug 06 2021