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%I #37 Aug 13 2020 14:02:28
%S 101073,101082,101100,101155,101199,102192,102299,103275,103293,
%T 103366,103399,103502,104332,104342,104352,104362,104372,104382,
%U 104392,104499,104602,105432,105442,105452,105462,105472,105482,105492,105493,105544,105577,105599,105702
%N Numbers with palindromic order 5.
%C See A261913 for definition.
%C 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 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 Chai Wah Wu, <a href="/A261912/b261912.txt">Table of n, a(n) for n = 1..2278</a>
%H Erich Friedman, <a href="https://erich-friedman.github.io/mathmagic/0699.html">Problem of the Month (June 1999)</a>
%H 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 Chai Wah Wu, <a href="/A261912/a261912-Wu.zip">Table of n, a(n) for n = 1..481384 (zipped file)</a>
%Y Cf. A002113, A261907, A261910, A261911, A261913, A262528.
%K nonn,base
%O 1,1
%A _N. J. A. Sloane_, Sep 10 2015
%E More terms from _Chai Wah Wu_, Sep 11 2015 and Sep 12 2015
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