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 A324298 #57 Sep 11 2021 17:16:30
%S A324298 3,9,15,21,25,27,33,39,41,45,51,57,63,67,69,73,75,81,87,89,93,99,105,
%T A324298 111,117,119,121,123,129,135,137,141,145,147,153,159,165,169,171,177,
%U A324298 183,185,189,195,197,201,207,211,213,217,219,223,225,231,233,237,243,249
%N A324298 Positive integers k such that 10*k+6 is equal to the product of two integers ending with 6 (A324297).
%C A324298 All the terms of this sequence are odd.
%C A324298 Why? If an integer 10*k+6 = (10*a+6) * (10*b+6), then k = 10*a*b + 6*(a+b) + 3, so k is odd. - _Bernard Schott_, May 13 2019
%H A324298 Stefano Spezia, <a href="/A324298/b324298.txt">Table of n, a(n) for n = 1..10000</a>
%F A324298 a(n) = (A324297(n) - 6)/10.
%F A324298 Conjecture: lim_{n->infinity} a(n)/a(n-1) = 1.
%F A324298 The conjecture is true since a(n) = (A324297(n) - 6)/10 and lim_{n->infinity} A324297(n)/A324297(n-1) = 1. - _Stefano Spezia_, Aug 21 2021
%e A324298 145 is a term because 26*56 = 1456 = 145*10 + 6. - _Bernard Schott_, May 13 2019
%t A324298 a={}; For[n=0,n<=250,n++,For[k=0,k<=n,k++,If[Mod[10*n+6,10*k+6]==0 && Mod[(10*n+6)/(10*k+6),10]==6 && 10*n+6>Max[10*a+6],AppendTo[a,n]]]]; a
%o A324298 (PARI) isok6(n) = (n%10) == 6; \\ A017341
%o A324298 isok(k) = {my(n=10*k+6, d=divisors(n)); fordiv(n, d, if (isok6(d) && isok6(n/d), return(1))); return (0);} \\ _Michel Marcus_, Apr 14 2019
%o A324298 (Python)
%o A324298 def aupto(lim): return sorted(set(a*b//10 for a in range(6, 10*lim//6+2, 10) for b in range(a, 10*lim//a+2, 10) if a*b//10 <= lim))
%o A324298 print(aupto(249)) # _Michael S. Branicky_, Aug 21 2021
%Y A324298 Cf. A017341, A053742 (ending with 5), A324297, A337856, A346389.
%K A324298 nonn,base
%O A324298 1,1
%A A324298 _Stefano Spezia_, Mar 16 2019