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 A338842 #14 Nov 20 2020 09:09:58
%S A338842 1,3,5,7,11,9,13,15,21,17,23,25,31,43,37,27,19,29,33,35,45,39,41,77,
%T A338842 49,73,81,71,47,79,65,51,61,55,57,63,53,67,59,87,85,91,83,93,101,75,
%U A338842 69,113,141,95,105,127,119,129,133,135,117,147,213,149,115,97,103,151,209,153,235,169,233,143,137,229
%N A338842 No even digit is present in a(n) * a(n+1).
%C A338842 This is the lexicographically earliest sequence of distinct positive terms with this property.
%H A338842 Carole Dubois, <a href="/A338842/b338842.txt">Table of n, a(n) for n = 1..5000</a>
%e A338842 a(1) * a(2) = 1 * 3 = 3 (no even digit is present);
%e A338842 a(2) * a(3) = 3 * 5 = 15 (no even digit is present);
%e A338842 a(3) * a(4) = 5 * 7 = 35 (no even digit is present); etc.
%t A338842 Block[{a = {1}}, Do[Block[{k = 3}, While[Nand[FreeQ[a, k], NoneTrue[IntegerDigits@ Total[a[[-1]]*k], EvenQ]], k += 2]; AppendTo[a, k]], {i, 2, 72}]; a] (* _Michael De Vlieger_, Nov 12 2020 *)
%Y A338842 Cf. A014261 (no even digits).
%Y A338842 Cf. A338839, A338840, A338841, A338843, A338844, A338845, A338846 (variants on the same idea).
%K A338842 nonn,base,look
%O A338842 1,2
%A A338842 _Eric Angelini_ and _Carole Dubois_, Nov 11 2020