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 A052061 #23 Oct 18 2019 21:24:18 %S A052061 0,1,2,3,4,5,6,7,8,9,13,14,16,17,18,19,23,24,25,27,28,29,31,32,33,36, %T A052061 37,39,41,42,43,44,48,49,51,52,53,54,55,57,59,61,64,66,68,69,71,72,73, %U A052061 74,75,78,79,82,84,86,87,89,93,95,96,97,98,99,104,113,116,117,118,124 %N A052061 Numbers k such that decimal expansion of k^2 contains no palindromic substring except single digits. %C A052061 Leading zeros in the substrings are allowed so 103^2 = 10609 is rejected because 1{060}9 contains a palindromic substring. %C A052061 Probabilistic analysis strongly suggests that this sequence is not finite. - _Franklin T. Adams-Watters_, Nov 15 2006 %H A052061 Charles R Greathouse IV, <a href="/A052061/b052061.txt">Table of n, a(n) for n = 1..10001</a> %e A052061 118^2 = 13924 -> substrings 13, 39, 92, 24, 139, 392, 924, 1392, 3924 and 13924 are all non-palindromic. %o A052061 (PARI) noPalSub(n)={my(d);local(digit);digit=eval(Vec(Str(n)));d = #digit;for(len=2,d,for(i=1,d-len+1,if(isPalSub(i,len), return(0))));1}; %o A052061 isPalSub(start,len)={my(b=start-1,e=start+len);for(j=1,len>>1,if(digit[b+j] != digit[e-j], return(0)));1}; %o A052061 for(n=0,200,if(noPalSub(n^2),print1(n", "))) %Y A052061 Cf. A052062, A052063, A052064, A050741. %K A052061 nonn,base %O A052061 1,3 %A A052061 _Patrick De Geest_, Jan 15 2000 %E A052061 Program and b-file from _Charles R Greathouse IV_, Sep 09 2009