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 A292846 #27 Jun 27 2025 18:37:34 %S A292846 166425621223026859056339052269787863565428, %T A292846 192910929628537040766341860254183960991698, %U A292846 307567270506730945853551459962385036145286,311906350108036145286307567270199935391877 %N A292846 Numbers k such that 11 iterations of 'Reverse and Subtract' lead to k, whereas fewer than 11 iterations do not lead to k. %C A292846 There are 11 forty-two-digit terms in the sequence. Further terms are obtained (a) by inserting at the center of these terms either any number of 0's (for 166425621223026859056339052269787863565428, 311906350108036145286307567270199935391877, 466287189883036620417374974360601118217236, 658139747564935391877311906350534262959233, 703288139752915027377325180481642968027593) or any number of 9's (for the other six terms) and (b) by concatenating a term any number of times with itself and inserting an equal number of 0's at all junctures. Method (b) may be applied recursively to all terms. - Clarified by _Ray Chandler_, Oct 14 2017. %H A292846 Ray Chandler, <a href="/A292846/b292846.txt">Table of n, a(n) for n = 1..11</a> %H A292846 J. H. E. Cohn, <a href="https://web.archive.org/web/2024*/https://www.fq.math.ca/Scanned/28-2/cohn.pdf">Palindromic differences</a>, Fibonacci Quart. 28 (1990), no. 2, 113-120. %F A292846 n = f^11(n), n <> f^k(n) for k < 11, where f: x -> |x - reverse(x)|. %e A292846 166425621223026859056339052269787863565428 -> 658139747564935391877311906350534262959233 -> 325180485129881782763533712811068515027377 -> 448540030730236434571833574377853069054146 -> 192910929628537040766341860254183960991698 -> 703288139752915027377325180481642968027593 -> 307567270506730945853551459962385036145286 -> 374974360076539008301807089075220036620417 -> 339052269946031972406296711860450026859056 -> 311906350108036145286307567270199935391877 -> 466287189883036620417374974360601118217236 -> 166425621223026859056339052269787863565428. %Y A292846 Cf. A072142, A072143, A072718, A072719, A215669, A292634, A292635, A292856, A292857, A292858, A292859. %K A292846 nonn,base %O A292846 1,1 %A A292846 _Meritxell Vila Miñana_, Sep 24 2017 %E A292846 Terms corrected by _Ray Chandler_, Sep 27 2017