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 A131931 #8 Sep 08 2018 03:11:13 %S A131931 1,2,132,735,21372,271362,4773132,113678565,11317129824 %N A131931 Smallest number containing exactly n prime factors in its decimal representation. %C A131931 A131929(a(n)) = n and A131929(m) <> n for m<a(n). %e A131931 a(2) = 2^2 * 3 * 11 = 132 containing 2 and 3; %e A131931 a(3) = 3 * 5 * 7^2 = 735 containing 3, 5 and 7; %e A131931 a(4) = 2^2 * 3 * 13 * 137 = 21372 containing 2, 3, 13 and 137; %e A131931 a(5) = 2 * 3 * 7^2 * 13 * 71 = 271362 containing 2, 3, 7, 13 and 71. %Y A131931 Cf. A131930, A131929, A318965. %K A131931 nonn,base,more %O A131931 0,2 %A A131931 _Reinhard Zumkeller_, Jul 30 2007 %E A131931 Offset changed by and a(6)-a(8) from _Giovanni Resta_, Sep 06 2018