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 A026425 #8 Mar 07 2016 08:31:53
%S A026425 1,4,5,6,7,8,9,10,11,12,13,14,15,17,18,19,21,22,23,26,27,29,31,33,34,
%T A026425 37,38,39,41,43,46,47,51,53,57,58,59,61,62,67,69,71,73,74,79,82,83,86,
%U A026425 87,89,93,94,97,101,103,106,107,109,111,113
%N A026425 a(n) = least positive integer > a(n-1) and not a(i)*a(j) for 1<=i<=j<=n, n >= 2.
%H A026425 Ivan Neretin, <a href="/A026425/b026425.txt">Table of n, a(n) for n = 1..1000</a>
%t A026425 a = {1, 4}; used = {a[[1]]^2, a[[1]]*a[[2]], a[[2]]^2}; Do[k = a[[-1]] + 1; While[MemberQ[used, k], k++]; AppendTo[a, k]; used = Union[used, k*a], {n, 3, 60}]; a (* _Ivan Neretin_, Mar 07 2016 *)
%Y A026425 Cf. A026416 and references therein.
%K A026425 nonn
%O A026425 1,2
%A A026425 _Clark Kimberling_