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 A071955 #15 Apr 05 2020 11:48:48
%S A071955 0,0,0,0,0,0,0,0,0,0,0,12,13,14,15,16,17,18,19,0,9,0,23,24,25,26,27,
%T A071955 28,29,0,5,9,0,34,35,36,37,38,39,0,13,18,9,0,45,46,47,48,49,0,6,2,18,
%U A071955 9,0,56,57,58,59,0,13,10,27,18,9,0,67,68,69,0,3,18,36,27,18,9,0,78,79,0,9
%N A071955 a(n) = remainder when n is reduced mod reverse(n).
%C A071955 a(n)=0 if n is palindromic - _Labos Elemer_, Jan 28 2005
%H A071955 Rémy Sigrist, <a href="/A071955/b071955.txt">Table of n, a(n) for n = 1..10000</a>
%e A071955 a(85) = 85 mod 58 = 27.
%t A071955 Table[Mod[n, FromDigits[Reverse[IntegerDigits[n]]]], {n, 1, 256}] (* _Labos Elemer_, Jan 28 2005 *)
%t A071955 Table[Mod[n, FromDigits[Reverse[IntegerDigits[n]]]], {n, 1, 100}]
%o A071955 (PARI) a(n, base=10) = my (r=fromdigits(Vecrev(digits(n, base)), base)); n%r \\ _Rémy Sigrist_, Apr 05 2020
%Y A071955 Cf. A002113, A071590, A103164, A103168.
%K A071955 base,nonn
%O A071955 1,12
%A A071955 _Joseph L. Pe_, Jun 16 2002
%E A071955 Edited by _N. J. A. Sloane_ at the suggestion of _Andrew S. Plewe_, Jul 14 2007