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A216955 Triangle read by rows: T(n,k) (n>=1, 1<=k<=n) = number of binary sequences of length n and curling number k. 21
2, 2, 2, 4, 2, 2, 6, 6, 2, 2, 12, 12, 4, 2, 2, 20, 26, 10, 4, 2, 2, 40, 52, 20, 8, 4, 2, 2, 74, 110, 38, 18, 8, 4, 2, 2, 148, 214, 82, 36, 16, 8, 4, 2, 2, 286, 438, 164, 70, 34, 16, 8, 4, 2, 2, 572, 876, 328, 140, 68, 32, 16, 8, 4, 2, 2, 1124, 1762, 660, 286, 134, 66, 32, 16, 8, 4, 2, 2, 2248, 3524, 1320, 572, 268, 132, 64, 32, 16, 8, 4, 2, 2 (list; table; graph; refs; listen; history; text; internal format)
OFFSET
1,1
COMMENTS
For definition of curling number see A216730.
"Binary" sequence means two-valued. It doesn't matter if the alphabet is {0,1} or {2,3}.
It appears that reversed rows converge to the sequence formed by the even terms of A090129. - Omar E. Pol, Nov 20 2012
LINKS
Benjamin Chaffin, John P. Linderman, N. J. A. Sloane and Allan Wilks, First 104 rows of A216955
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
Triangle begins:
2,
2, 2,
4, 2, 2,
6, 6, 2, 2,
12, 12, 4, 2, 2,
20, 26, 10, 4, 2, 2,
40, 52, 20, 8, 4, 2, 2,
74, 110, 38, 18, 8, 4, 2, 2,
148, 214, 82, 36, 16, 8, 4, 2, 2,
286, 438, 164, 70, 34, 16, 8, 4, 2, 2,
...
CROSSREFS
Leading columns are A122536 (or A093371), A217211, A217212. Cf. A216956, A217943.
Sequence in context: A368556 A134058 A345530 * A086973 A240131 A029640
KEYWORD
nonn,tabl
AUTHOR
N. J. A. Sloane, Sep 26 2012
EXTENSIONS
Extended to 104 rows by N. J. A. Sloane, Nov 15 2012
STATUS
approved

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Last modified March 19 04:58 EDT 2024. Contains 370952 sequences. (Running on oeis4.)