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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

%I

%S 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,

%T 110,38,18,8,4,2,2,148,214,82,36,16,8,4,2,2,286,438,164,70,34,16,8,4,

%U 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

%N Triangle read by rows: T(n,k) (n>=1, 1<=k<=n) = number of binary sequences of length n and curling number k.

%C For definition of curling number see A216730.

%C "Binary" sequence means two-valued. It doesn't matter if the alphabet is {0,1} or {2,3}.

%C It appears that reversed rows converge to the sequence formed by the even terms of A090129. - _Omar E. Pol_, Nov 20 2012

%H N. J. A. Sloane, <a href="/A216955/b216955.txt">Table of n, a(n) for n = 1..5460</a>

%H Benjamin Chaffin, John P. Linderman, N. J. A. Sloane and Allan Wilks, <a href="/A216955/a216955.txt">First 104 rows of A216955</a>

%H B. Chaffin, J. P. Linderman, N. J. A. Sloane and Allan Wilks, <a href="http://arxiv.org/abs/1212.6102">On Curling Numbers of Integer Sequences</a>, arXiv:1212.6102, Dec 25 2012.

%H B. Chaffin, J. P. Linderman, N. J. A. Sloane and Allan Wilks, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL16/Sloane/sloane3.html">On Curling Numbers of Integer Sequences</a>, Journal of Integer Sequences, Vol. 16 (2013), Article 13.4.3.

%H <a href="/index/Cu#curling_numbers">Index entries for sequences related to curling numbers</a>

%e Triangle begins:

%e 2,

%e 2, 2,

%e 4, 2, 2,

%e 6, 6, 2, 2,

%e 12, 12, 4, 2, 2,

%e 20, 26, 10, 4, 2, 2,

%e 40, 52, 20, 8, 4, 2, 2,

%e 74, 110, 38, 18, 8, 4, 2, 2,

%e 148, 214, 82, 36, 16, 8, 4, 2, 2,

%e 286, 438, 164, 70, 34, 16, 8, 4, 2, 2,

%e ...

%Y Leading columns are A122536 (or A093371), A217211, A217212. Cf. A216956, A217943.

%K nonn,tabl

%O 1,1

%A _N. J. A. Sloane_, Sep 26 2012

%E Extended to 104 rows by _N. J. A. Sloane_, Nov 15 2012

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Last modified November 18 04:43 EST 2019. Contains 329248 sequences. (Running on oeis4.)