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 A318965 #19 Sep 08 2018 12:45:32
%S A318965 2,135,735,21372,271362,4773132,113678565,11317129824,131175822960,
%T A318965 7113719552940,255360234137190,12411792985131540
%N A318965 a(n) is the smallest number containing all its n prime factors in its decimal representation.
%e A318965 a(2) = 135 = 3^3 * 5,
%e A318965 a(3) = 735 = 3 * 5 * 7^2,
%e A318965 a(4) = 21372 = 2^2 * 3 * 13 * 137,
%e A318965 a(5) = 271362 = 2 * 3 * 7^2 * 13 * 71,
%e A318965 a(6) = 4773132 = 2^2 * 3^2 * 7 * 13 * 31 * 47.
%e A318965 a(7) = 113678565 = 3 * 5 * 7 * 11 * 13 * 67 * 113.
%t A318965 a[n_] := Block[{k=1, s, f}, While[True, k++; If[Length[f = FactorInteger[k]] == n, s = ToString@k; If[AllTrue[First /@ f, StringPosition[s, ToString@ #] != {} &], Break[]]]]; k]; Array[a, 5]
%Y A318965 Cf. A131929, A131930, A131931, A239060, A115738.
%K A318965 nonn,base,more
%O A318965 1,1
%A A318965 _Giovanni Resta_, Sep 06 2018