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A216951 Let S be a string of n 2's and 3's, with curling number k, which means S = XY^k where k is maximized; a(n) = number of S for which X must be taken to be the empty string. 2
2, 2, 2, 4, 2, 8, 2, 10, 8, 14, 2, 40, 2, 40, 32, 88, 2, 192, 2, 324, 100, 564, 2, 1356, 32, 2226, 370, 4564, 2, 9656, 2, 17944, 1450, 35424, 152, 74182, 2, 141628, 5774, 284342, 2, 578022, 2, 1134518, 23576, 2265394, 2, 4580468, 128, 9062280, 92236, 18129626 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
See A216730 for definition of curling number.
LINKS
B. Chaffin, J. P. Linderman, N. J. A. Sloane and Allan Wilks, On Curling Numbers of Integer Sequences, arXiv:1212.6102, 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
For n=6, there are 8 strings S that satisfy the condition:
222222, k=6, Y=2
223223, k=2, Y=223
232232, k=2, Y=232
232323, k=3, Y=23
and 4 more by exchanging 2 and 3. Note that 233233 with k=2 is not on the list, because we could choose X empty, Y=233 or X=2332, Y=3, and the latter avoids taking X to be empty.
CROSSREFS
Sequence in context: A278242 A035580 A135293 * A366628 A320305 A064025
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Sep 24 2012
EXTENSIONS
More terms from Lars Blomberg, Nov 02 2016
STATUS
approved

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Last modified March 19 03:33 EDT 2024. Contains 370952 sequences. (Running on oeis4.)