A075107 Number of steps to reach the first integer (= A075108(n)) starting with n/floor(log_2(n)) and iterating the map x -> x*ceiling(x), or -1 if no integer is ever reached.

0, 0, 0, 2, 0, 1, 1, 0, 5, 2, 0, 3, 2, 0, 0, 3, 3, 2, 0, 2, 1, 3, 0, 2, 2, 2, 0, 1, 1, 1, 2, 5, 3, 0, 16, 2, 4, 6, 0, 4, 16, 9, 2, 0, 1, 1, 1, 1, 0, 4, 2, 4, 8, 0, 2, 5, 2, 8, 0, 9, 3, 4, 5, 2, 0, 1, 1, 1, 1, 1, 0, 5, 7, 3, 2, 4, 0, 9, 4, 1, 2, 3, 0, 4, 1, 2, 1

Offset

2,4

Comments

Starting values given by A075105(n)/A075106(n).

Links

Table of n, a(n) for n=2..88.

Example

a(5)=2 since 5/floor(log_2(5)) = 5/2 -> 15/2 -> 60 = A075108(5).

Crossrefs

Cf. A068119, A073524, A075102, A075120.

Sequence in context: A158800 A144024 A185249 * A269953 A326411 A348454

Adjacent sequences: A075104 A075105 A075106 * A075108 A075109 A075110

Keyword

nonn

Author

Reinhard Zumkeller, Sep 02 2002

Extensions

More terms from Jinyuan Wang, Jan 15 2022

Status

approved