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 A180458 #13 Dec 18 2020 16:14:25
%S A180458 2,3,5,7,11,11,11,11,22,22,22,33,33,33,44,44,55,55,66,66,66,77,77,88,
%T A180458 88,101,101,101,101,111,121,131,131,131,141,151,151,161,161,171,171,
%U A180458 181,191,191,191,191,202,222,222,222,232,232,232,242,252,262,262,262,272
%N A180458 Largest palindromic number <= n-th-prime.
%H A180458 Robert Israel, <a href="/A180458/b180458.txt">Table of n, a(n) for n = 1..10000</a>
%p A180458 # given lists Primes of primes and Palis of palindromes, with Palis[-1] > Primes[-1]
%p A180458 m:= 1; A:= 'A':
%p A180458 for n from 1 to nops(Primes) do
%p A180458 while m < nops(Palis) and Palis[m+1] <= Primes[n] do m:= m+1 od:
%p A180458 A[n]:= Palis[m]
%p A180458 od:
%p A180458 seq(A[i],i=1..nops(Primes)); # _Robert Israel_, Apr 26 2016
%t A180458 lpn[n_]:=Module[{k=0},While[!PalindromeQ[n-k],k++];n-k]; Table[lpn[n],{n,Prime[Range[60]]}] (* Requires Mathematica version 10 or later *) (* _Harvey P. Dale_, Dec 18 2020 *)
%Y A180458 Cf. A000040, A261423.
%K A180458 base,nonn
%O A180458 1,1
%A A180458 _Giovanni Teofilatto_, Sep 06 2010
%E A180458 Corrected by _Robert Israel_, Apr 26 2016