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 A087993 #10 Dec 31 2023 16:57:46 %S A087993 45,54,495,594,4356,4545,4995,5454,5895,5985,5994,6534,10890,19602, %T A087993 20691,29403,30492,39204,40293,43956,45045,49005,49995,50094,54054, %U A087993 59994,65934,68607,70686,77319,91377,109890,197802,208791,296703,307692 %N A087993 Numbers k for which the quotient q(k)=(k+rev(k))/abs(k-rev(k)) is an integer. %H A087993 Giovanni Resta, <a href="/A087993/b087993.txt">Table of n, a(n) for n = 1..500</a> %e A087993 n = 45, rev(n) = 54, q = 99/9 = 9 integer; %e A087993 n = 934065, rev(n) = 560434, q = 1494504/373626 = 4, integer. %t A087993 rev[n_] := FromDigits@ Reverse@ IntegerDigits@ n; Select[Range[10^5], # != (r = rev[#]) && Mod[# + r, # - r] == 0 &] (* _Giovanni Resta_, May 14 2017 *) %Y A087993 Cf. A087994 (the quotients), A118959. %K A087993 base,nonn %O A087993 1,1 %A A087993 _Labos Elemer_, Oct 08 2003