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 A069747 #16 Jun 09 2020 10:59:58
%S A069747 1,2,3,4,5,6,7,8,9,535,767,20502,50805,53035,58085,58585,59395,82428,
%T A069747 88188,3269623,5808085,5846485,8110118,8666668,8818188,8872788,
%U A069747 8875788,473040374,515050515,530303035,535353535,580303085,580858085,581585185,585797585
%N A069747 Numbers n such that n and phi(n) are both palindromes.
%C A069747 For an arithmetical function f, call the pairs (x,y) such that y = f(x) and x, y are palindromes the "palinpairs" of f. a(n) is then the sequence of abscissae of palinpairs of f(n) = phi(n).
%H A069747 Giovanni Resta, <a href="/A069747/b069747.txt">Table of n, a(n) for n = 1..766</a> (terms < 10^19)
%e A069747 phi(58085) = 46464, so 58085 is a term of the sequence.
%t A069747 isPalin[n_] := (n == FromDigits[Reverse[IntegerDigits[n]]]); Do[m = EulerPhi[n]; If[isPalin[n] && isPalin[m], Print[{n, m}]], {n, 1, 10^6}]
%K A069747 nonn,base
%O A069747 1,2
%A A069747 _Joseph L. Pe_, Apr 22 2002
%E A069747 More terms from _Jason Earls_, May 07 2002