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 A261912 #37 Aug 13 2020 14:02:28 %S A261912 101073,101082,101100,101155,101199,102192,102299,103275,103293, %T A261912 103366,103399,103502,104332,104342,104352,104362,104372,104382, %U A261912 104392,104499,104602,105432,105442,105452,105462,105472,105482,105492,105493,105544,105577,105599,105702 %N A261912 Numbers with palindromic order 5. %C A261912 See A261913 for definition. %C A261912 In the Friedman Problem of the Month page, there is a statement by John Hoffman which, if I have interpreted it correctly, asserts that this sequence has only a finite number of terms. However, Chai Wah Wu has extended the sequence out to 10^8, finding 481384 terms, the last one being a(481384) = 99998180. This sequence does not appear to be finite. %C A261912 The first terms of this sequence are just beyond A109326(5). It can be expected that at least beyond A109326(6) = 1000101024 there will be examples where N-prevpal(N) and N-prevpal(prevpal(N)) are both of order 5; these numbers could be termed to be of order 6, and so on. - _M. F. Hasler_, Sep 13 2015 %H A261912 Chai Wah Wu, <a href="/A261912/b261912.txt">Table of n, a(n) for n = 1..2278</a> %H A261912 Erich Friedman, <a href="https://erich-friedman.github.io/mathmagic/0699.html">Problem of the Month (June 1999)</a> %H A261912 M. F. Hasler, <a href="/wiki/User:M._F._Hasler/Work_in_progress/Sum_of_palindromes">Sum of palindromes</a>, OEIS wiki, Sep 10 2015 %H A261912 Chai Wah Wu, <a href="/A261912/a261912-Wu.zip">Table of n, a(n) for n = 1..481384 (zipped file)</a> %Y A261912 Cf. A002113, A261907, A261910, A261911, A261913, A262528. %K A261912 nonn,base %O A261912 1,1 %A A261912 _N. J. A. Sloane_, Sep 10 2015 %E A261912 More terms from _Chai Wah Wu_, Sep 11 2015 and Sep 12 2015