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 A103168 #17 Jun 20 2025 16:07:24
%S A103168 0,0,0,0,0,0,0,0,0,1,0,9,5,13,6,13,3,9,15,2,12,0,9,18,2,10,18,26,5,3,
%T A103168 13,23,0,9,18,27,36,7,15,4,14,24,34,0,9,18,27,36,45,5,15,25,35,45,0,9,
%U A103168 18,27,36,6,16,26,36,46,56,0,9,18,27,7,17,27,37,47,57,67,0,9,18,8,18,28,38
%N A103168 a(n) is the remainder when (n written backwards) is divided by n.
%H A103168 Rémy Sigrist, <a href="/A103168/b103168.txt">Table of n, a(n) for n = 1..10000</a>
%e A103168 a(n) = 0 for palindromic numbers.
%t A103168 rd[x_]:=FromDigits[Reverse[IntegerDigits[x]]] Table[Mod[rd[n], n], {n, 1, 256}]
%t A103168 Table[Mod[IntegerReverse[n],n],{n,90}] (* _Harvey P. Dale_, Jun 20 2025 *)
%o A103168 (PARI) a(n, base=10) = my (r=fromdigits(Vecrev(digits(n, base)), base)); r%n \\ _Rémy Sigrist_, Apr 05 2020
%o A103168 (Python)
%o A103168 def a(n): return int(str(n)[::-1])%n
%o A103168 print([a(n) for n in range(1, 84)]) # _Michael S. Branicky_, Dec 12 2021
%Y A103168 Cf. A071955, A103166-A103169, A002113, A071590.
%K A103168 base,nonn
%O A103168 1,12
%A A103168 _Labos Elemer_, Jan 28 2005
%E A103168 Definition corrected by _N. J. A. Sloane_, Jul 14 2007