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 A217437 Number of strings of length n in {2,3}* for which at least one of tail(2 S) > tail(S) and tail(3 S) > tail(S) holds. 0
 2, 1, 2, 1, 5, 3, 12, 9, 19, 16, 38, 20, 59, 42, 104, 65, 213, 111, 400, 245, 765, 439, 1563, 820, 3046, 1731, 5955, 3292, 12078, 6343, 23841, 13090, 47204, 25534, 95140, 50154 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The "curling number" k = k(S) of a string of numbers S = s(1), ..., s(m) is defined as follows. Write S as XY^k for strings X and Y (where Y has positive length) and k is maximized, i.e. k = the maximal number of repeating blocks at the end of S. The "tail length" tail(S) of S is defined as follows: start with S and repeatedly append the curling number (recomputing it at each step) until a 1 is reached; tail(S) is the number of terms that are appended to S before a 1 is reached. No example is known where both tail(2 S) > tail(S) and tail(3 S) > tail(S) hold. LINKS B. Chaffin, J. P. Linderman, N. J. A. Sloane and Allan Wilks, On Curling Numbers of Integer Sequences, arXiv:1212.6102 [math.CO], Dec 25 2012. B. Chaffin, J. P. Linderman, N. J. A. Sloane and Allan Wilks, On Curling Numbers of Integer Sequences, Journal of Integer Sequences, Vol. 16 (2013), Article 13.4.3. EXAMPLE Tail(22322)=2, tail(222322)=8, tail(322322)=2, so 22322 is counted in a(5). CROSSREFS Sequence in context: A102048 A318360 A102551 * A152823 A086545 A126083 Adjacent sequences:  A217434 A217435 A217436 * A217438 A217439 A217440 KEYWORD nonn,more AUTHOR Benjamin Chaffin, Oct 02 2012 EXTENSIONS a(31)-a(36) from Lars Blomberg, Nov 01 2016 STATUS approved

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Last modified January 20 12:32 EST 2019. Contains 319330 sequences. (Running on oeis4.)