A075102 Number of steps to reach the first integer starting with 2^n/n and iterating the map x->x*ceiling(x), or -1 if no integer is ever reached.

0, 0, 1, 0, 2, 5, 5, 0, 2, 4, 1, 1, 13, 12, 3, 0, 19, 3, 4, 8, 10, 11, 20, 1, 7, 1, 3, 8, 12, 1, 2, 0, 20, 6, 4, 7, 8, 23, 39, 1, 21, 8, 13, 16, 4, 1, 9, 7, 1, 6, 23, 30, 73, 6, 3, 14, 7, 7, 20, 12, 228, 16, 3, 0, 10, 5, 96, 3, 4, 13, 28, 3, 72, 57, 7, 9, 6, 6

Offset

1,5

Comments

The starting value is A075101(n)/A000265(n).

Links

Table of n, a(n) for n=1..78.

J. C. Lagarias and N. J. A. Sloane, Approximate squaring (pdf, ps), Experimental Math., 13 (2004), 113-128.

Example

a(5)=2 since (2^5)/5 = 32/5 -> 224/5 -> 2016 = A075103(5).

Crossrefs

Cf. A000265, A068119, A073524, A075101, A075103.

Sequence in context: A206484 A061083 A177039 * A209883 A326050 A361590

Adjacent sequences: A075099 A075100 A075101 * A075103 A075104 A075105

Keyword

nonn

Author

Reinhard Zumkeller, Sep 02 2002

Extensions

More terms from Jinyuan Wang, Jan 15 2022

Status

approved