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 A030547 Number of terms (including the initial term) needed to reach a palindrome when the Reverse Then Add! map (x -> x + (x-with-digits-reversed)) is repeatedly applied to n, or -1 if a palindrome is never reached. 2
 1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 2, 2, 2, 2, 2, 2, 3, 2, 2, 1, 2, 2, 2, 2, 2, 3, 2, 2, 2, 2, 1, 2, 2, 2, 3, 2, 3, 2, 2, 2, 2, 1, 2, 3, 2, 3, 3, 2, 2, 2, 2, 2, 1, 2, 3, 3, 4, 2, 2, 2, 2, 3, 2, 1, 3, 4, 5, 2, 2, 2, 3, 2, 3, 3, 1, 5, 7, 2, 2, 3, 2, 3, 3, 4, 5, 1, 25, 2, 3, 2, 3, 3, 4, 5, 7, 25 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,10 COMMENTS It is conjectured that a(196) is the smallest term equal to -1. See A023108. REFERENCES Daniel Lignon, Dictionnaire de (presque) tous les nombres entiers, Ellipses, Paris, 2012, 702 pages. See Entry 196. LINKS Eric Weisstein's World of Mathematics, 196 Algorithm. MATHEMATICA Table[Length@   NestWhileList[# + IntegerReverse[#] &, n, ! PalindromeQ[#]  &], {n, 98}] (* Robert Price, Oct 18 2019 *) CROSSREFS Cf. A006960, A023108, A063018, etc. Equals A033665(n) + 1. Sequence in context: A094916 A036485 A331971 * A339932 A254690 A156642 Adjacent sequences:  A030544 A030545 A030546 * A030548 A030549 A030550 KEYWORD nonn,base AUTHOR EXTENSIONS Edited by N. J. A. Sloane, May 09 2015 STATUS approved

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Last modified November 28 13:47 EST 2021. Contains 349413 sequences. (Running on oeis4.)