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 A026435 #15 Feb 06 2025 13:50:57
%S A026435 2,4,5,6,8,10,12,13,14,16,17,18,20,21,22,24,26,28,30,32,34,36,37,38,
%T A026435 40,42,44,45,46,48,50,52,53,54,56,57,58,60,61,62,65,66,68,70,72,74,76,
%U A026435 78,80,81,82,85,86,88,90,92,93,94,96,97
%N A026435 a(n) = least positive integer > a(n-1) and not a(i)*a(j)-1 for 1<=i<j<=n, with initial terms 2,4.
%H A026435 Ivan Neretin, <a href="/A026435/b026435.txt">Table of n, a(n) for n = 1..1000</a>
%t A026435 a = {2, 4}; used = {a[[1]]*a[[2]] - 1}; Do[k = a[[-1]] + 1; While[MemberQ[used, k], k++]; used = Union[used, k*a - 1]; AppendTo[a, k], {n, 3, 60}]; a (* _Ivan Neretin_, Mar 07 2016 *)
%Y A026435 Cf. A026431 and references therein.
%K A026435 nonn
%O A026435 1,1
%A A026435 _Clark Kimberling_
%E A026435 Name clarified by _Robert C. Lyons_, Feb 06 2025