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 A316497 #15 Jul 05 2018 04:30:14 %S A316497 2,2,2,2,11,11,11,11,11,11,11,3,3,3,3,2,2,2,2,2,2,2,4,2,2,2,2,2,2,2,2, %T A316497 2,13,5,7,2,2,2,2,2,2,2,2,3,3,3,3,2,2,2,2,2,2,2,2,22,22,22,22,22,22, %U A316497 22,22,22,11,11,11,11,11,11,11,11,11,11,11,22,22,22,22,22,22,22,22,22,11,55 %N A316497 a(n) = gcd(A081939(n), A081939(n+1)). %H A316497 Robert Israel, <a href="/A316497/b316497.txt">Table of n, a(n) for n = 1..10000</a> %H A316497 <a href="/index/Pac#palindromes">Index entries for sequences related to palindromes</a> %e A316497 A081939(3)=6 and A081939(4)=8, so a(3)=gcd(6,8)=2. %p A316497 # with list R containing terms of A081939 %p A316497 seq(igcd(R[i],R[i+1]),i=1..nops(R)-1) %Y A316497 Cf. A081939. %K A316497 nonn,base %O A316497 1,1 %A A316497 _Robert Israel_, Jul 04 2018