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 A115741 #2 Mar 30 2012 17:40:35 %S A115741 6,10,51,55,82,87,309,501,649,694,1198,1207,1473,1765,1803,1837,1959, %T A115741 1981,3043,3057,3561,3574,5158,5221,5721,6139,6193,6267,6535,6711, %U A115741 6814,6843,10473,10497,11553,12477,12693,13123,13701,13951,14169 %N A115741 Semiprimes (A001358) whose digit reversal is a triangular number. %e A115741 51=3*17 is semiprime and 15=T(5). %Y A115741 Cf. A001358, A115742. %K A115741 nonn,base %O A115741 1,1 %A A115741 _Giovanni Resta_, Jan 31 2006