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A015980 Four iterations of Reverse and Add are needed to reach a palindrome. 2
69, 78, 87, 96, 174, 175, 181, 183, 191, 192, 195, 273, 274, 280, 282, 290, 291, 294, 372, 373, 381, 390, 393, 471, 472, 480, 492, 539, 570, 571, 579, 591, 599, 629, 638, 649, 670, 678, 679, 690, 698, 699, 728, 729, 737, 748, 749, 769, 777 (list; graph; refs; listen; history; text; internal format)
OFFSET
0,1
COMMENTS
The number of iterations starts at 1, so palindromes (cf. A002113) are not excluded. The corresponding sequence excluding palindromes is A065209.
LINKS
MATHEMATICA
ra4Q[n_]:=With[{c=Rest[NestList[#+IntegerReverse[#]&, n, 4]]}, PalindromeQ[ Last[c]] && NoneTrue[Most[c], PalindromeQ]]; Select[Range[800], ra4Q] (* Requires Mathematica version 10 or later *) (* Harvey P. Dale, May 28 2018 *)
CROSSREFS
Sequence in context: A295806 A210614 A235226 * A065209 A045021 A254712
KEYWORD
nonn,base
AUTHOR
STATUS
approved

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Last modified July 12 17:07 EDT 2024. Contains 374251 sequences. (Running on oeis4.)