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 A155509 #7 Apr 04 2019 17:30:02
%S A155509 991,99119,191911,911111,919111,999199,1911911,1991911,9111911,
%T A155509 11911111,19911191,19919111,19991911,99111119,911111191,991111111,
%U A155509 991991111,999199991,999919919,1911119911,1919991191,1991111911,1991919191
%N A155509 Larger of emirps (pairs) with digits 1 and 9 only.
%H A155509 Harvey P. Dale, <a href="/A155509/b155509.txt">Table of n, a(n) for n = 1..1000</a>
%t A155509 le19[n_]:=Module[{emrps=Select[FromDigits/@Tuples[{1,9},n],!PalindromeQ[ #] && AllTrue[ {#,IntegerReverse[#]},PrimeQ]&]},If[IntegerReverse[#]>#, IntegerReverse[ #],{}]&/@emrps/.{}->Nothing]; Flatten[Table[le19[x],{x,10}]] // Sort (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Apr 04 2019 *)
%Y A155509 A006567, A155507, A155508
%K A155509 nonn,base
%O A155509 1,1
%A A155509 _Lekraj Beedassy_, Jan 23 2009
%E A155509 More terms from _Sean A. Irvine_, Apr 06 2010