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 A113940 #10 Nov 21 2013 12:48:46
%S A113940 6,10,15,21,253,703,1081,1711,1891,2701,3403,25651,34453,38503,49141,
%T A113940 60031,64261,73153,79003,88831,104653,108811,114481,126253,146611,
%U A113940 158203,171991,188191,218791,226801,258121,269011,286903,351541,371953,385003,392941
%N A113940 Triangular numbers that are also brilliant (A078972).
%C A113940 Smallest value where each factor has n digits for n = 1, 2, 3, 4, 5, are: 6 = 2 * 3; 253 = 11 * 23; 25651 = 113 * 227; 2035153 = 1009 * 2017; 202457503 = 10061 * 20123. [From _Jonathan Vos Post_, Apr 04 2009]
%H A113940 Donovan Johnson, <a href="/A113940/b113940.txt">Table of n, a(n) for n = 1..1000</a>
%F A113940 A000217 INTERSECTION A078972. Subset of A068443. [From _Jonathan Vos Post_, Apr 04 2009]
%e A113940 253 = T(22) and 253 = 11*23 is brilliant.
%t A113940 brilQ[n_]:=Module[{fin=FactorInteger[n]},Total[Transpose[fin][[2]]]==2&& Length[Union[IntegerLength[Transpose[fin][[1]]]]]==1]
%t A113940 Intersection[Accumulate[Range[850]],Select[Range[362000],brilQ]] (* _Harvey P. Dale_, Feb 06 2011 *)
%Y A113940 Cf. A068443, A078972, A000217.
%K A113940 base,nonn
%O A113940 1,1
%A A113940 _Giovanni Resta_, Jan 31 2006