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 A262087 #11 Sep 18 2018 10:50:19
%S A262087 0,1,2,3,4,5,6,7,8,9,9,11,11,11,11,11,11,11,11,11,11,0,22,22,22,22,22,
%T A262087 22,22,22,22,22,0,33,33,33,33,33,33,33,33,33,33,0,44,44,44,44,44,44,
%U A262087 44,44,44,44,0,55,55,55,55,55,55,55,55,55,55,0,66,66,66,66,66,66,66,66,66,66,0,77,77,77,77,77,77
%N A262087 Largest palindrome p such that n-p is again a palindrome, or 0 if no such p exists.
%H A262087 Markus Sigg, <a href="/A262087/b262087.txt">Table of n, a(n) for n = 0..10000</a>
%F A262087 a(n) = 0 for n in {0} union A035137.
%o A262087 (PARI) a(N,P=A261423(N))=until(N<2*P=A261423(P-1),is_A002113(N-P)&&return(P))
%Y A262087 Cf. A261423, A002113, A035137.
%K A262087 nonn,base
%O A262087 0,3
%A A262087 _M. F. Hasler_, Sep 10 2015