A262303 Length of sequence of lower halves of n: repeatedly apply x->floor(x/2) starting at n; a(n) = number of steps until reach one of 2,3,4.

0, 0, 0, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5

Offset: 2

Author

N. J. A. Sloane, Sep 30 2015

Keywords

• nonn
• easy

Examples

			20->10->5->2 takes 3 steps, so a(20)=3.
		

Links

• S. Jablan, L. H. Kauffman, and P. Lopes, The delunification process and minimal diagrams, arXiv:1406.2378 [math.GT], 2014.
• S. Jablan, L. H. Kauffman, and P. Lopes, The delunification process and minimal diagrams, Topology Appl., 193 (2015), 270-289, #5531.

Crossrefs

Cf. A262304.

Extensions

a(31)-a(88) from Hiroaki Yamanouchi, Oct 03 2015