A217209 Irregular triangle read by rows: T(n,k) (n>=1, 1 <= k <= A217208(n)) = number of strings of n 2's and 3's having a tail of length k.

2, 2, 1, 1, 4, 2, 2, 6, 5, 3, 1, 1, 12, 9, 6, 2, 3, 20, 18, 12, 6, 7, 0, 0, 0, 1, 40, 34, 25, 11, 14, 1, 0, 1, 2, 74, 71, 47, 24, 28, 1, 3, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 1

Offset: 1

Author

N. J. A. Sloane, Oct 01 2012

Keywords

• nonn
• tabf

Comments

See A217208 or A216730 for definition of tail.

Examples

			Rows 1 through 8 are:
2,
2, 1, 1,
4, 2, 2,
6, 5, 3, 1, 1,
12, 9, 6, 2, 3,
20, 18, 12, 6, 7, 0, 0, 0, 1,
40, 34, 25, 11, 14, 1, 0, 1, 2,
74, 71, 47, 24, 28, 1, 3, 2, 3, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 1,
148, 139, 95, 48, 56, 6, 4, 3, 6, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 2, 3, 1, 1,
...
		

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.
• Ben Chaffin and N. J. A. Sloane, Rows 1 through 48 [The first 35 rows were computed by _N. J. A. Sloane_]
• Index entries for sequences related to curling numbers

Crossrefs

Cf. A217208 (row lengths), A216813 (means), A122536 (first column), A217210 (second column), A216730, A094004, A090822.