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 A261908 #13 Sep 09 2015 15:07:39 %S A261908 9,90,99,180,189,270,279,360,369,450,459,540,549,630,639,720,729,810, %T A261908 819,900,990,999,1089,1179,1269,1359,1449,1539,1629,1719,1728,1800, %U A261908 1809,1908,1980,2079,2088,2268,2358,2448 %N A261908 Numbers of the form |m - R(m)| for m in A035137, where R(m) denotes the digit-reversal of m. %C A261908 Created in an attempt to understand A035137. It would be nice to have an independent definition of these numbers. Obviously they are multiples of 9 - see A261909. %e A261908 21, 102, 1031 are some early terms in A035137, so this sequence contains 21-12=9, 201-102=99, 1301-1031=270. %Y A261908 Cf. A002113, A035137, A261909. %K A261908 nonn,base %O A261908 1,1 %A A261908 _N. J. A. Sloane_, Sep 09 2015