login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Triangle read by rows: T(n,k) (1 <= k <= n) = number of robust primitive binary sequences of length n and curling number k.
3

%I #26 Aug 02 2014 06:14:09

%S 2,2,0,4,2,0,6,4,2,0,10,12,4,2,0,20,20,8,4,2,0,36,52,20,8,4,2,0,72,98,

%T 36,16,8,4,2,0,142,214,76,36,16,8,4,2,0,280,414,160,68,32,16,8,4,2,0,

%U 560,870,326,140,68,32,16,8,4,2,0,1114,1720,640,276,132,64,32,16,8,4,2,0

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

%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 N. J. A. Sloane, <a href="/A218875/a218875.txt">First 36 rows of table</a>

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

%F The triangle in A218869 is the sum of triangles A218875 and A218876.

%e Triangle begins:

%e [2],

%e [2, 0],

%e [4, 2, 0],

%e [6, 4, 2, 0],

%e [10, 12, 4, 2, 0],

%e [20, 20, 8, 4, 2, 0],

%e [36, 52, 20, 8, 4, 2, 0],

%e [72, 98, 36, 16, 8, 4, 2, 0],

%e [142, 214, 76, 36, 16, 8, 4, 2, 0],

%e [280, 414, 160, 68, 32, 16, 8, 4, 2, 0],

%e ...

%Y Cf. A216955, A218869, A218876. First column is A216958.

%K nonn,tabl

%O 1,1

%A _N. J. A. Sloane_, Nov 15 2012