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 A244542 #15 Aug 14 2025 11:45:23
%S A244542 1,2,3,4,101,202,252,303,404,505,606,707,808,909,1001,2002,3003,4004,
%T A244542 5005,6006,7007,8008,9009,10001,10101,10201,10301,10401,10501,10601,
%U A244542 10701,10801,10901,11011,12021,13031,14041,15051,15451,16061,17071,18081,19091,20002,20102,20202
%N A244542 Palindromes n such that n +/- the product of digits of n are both palindromes.
%C A244542 These are the palindromes in A244541.
%C A244542 All palindromes with a zero will be in this sequence.
%C A244542 The palindromes that do not contain a zero but do satisfy the definition begin 1, 2, 3, 4, 252, 15451, 25152, 25252, 25352, 25452, 36563, 51415, 52125, 52225, 52325, 52425, 63536, 92529, 1455541, 1545451, 1954591 . . . - _Harvey P. Dale_, May 14 2019
%e A244542 101 - 1*0*1 and 101 + 1*0*1 are both palindromes (still 101). So 101 is a member of this sequence.
%t A244542 Select[Range[30000],AllTrue[#+{0,Times@@IntegerDigits[#],-Times@@IntegerDigits[#]},PalindromeQ]&] (* _Harvey P. Dale_, Aug 14 2025 *)
%o A244542 (PARI) rev(n)={r="";for(i=1,#digits(n),r=concat(Str(digits(n)[i]),r));return(eval(r))}
%o A244542 for(n=1,10^5,if(rev(n)==n,dig=digits(n);p=prod(k=1,#dig,dig[k]);mi=n-p;ma=n+p;if(rev(mi)==mi&&rev(ma)==ma,print1(n,", "))))
%Y A244542 Cf. A007954, A244541.
%K A244542 nonn,base
%O A244542 1,2
%A A244542 _Derek Orr_, Jun 29 2014