A075120 Number of steps to reach the first integer (= A075121(n)) starting with n/floor(sqrt(n)) and iterating the map x -> x*ceiling(x), or -1 if no integer is ever reached.

0, 0, 0, 0, 2, 0, 1, 0, 0, 5, 2, 0, 3, 2, 0, 0, 3, 3, 2, 0, 2, 1, 3, 0, 0, 8, 3, 5, 2, 0, 3, 2, 5, 3, 0, 0, 6, 2, 2, 4, 2, 0, 5, 3, 1, 4, 2, 0, 0, 7, 12, 5, 11, 12, 2, 0, 4, 3, 9, 12, 6, 16, 0, 0, 3, 7, 8, 4, 4, 4, 2, 0, 2, 4, 5, 1, 5, 2, 5, 0, 0, 7, 3, 22, 3, 3

Offset

1,5

Comments

Starting with A073890(n)/A075119(n).

Links

Table of n, a(n) for n=1..86.

Example

a(13)=3 since 13/floor(sqrt(13)) = 13/3 -> 65/3 -> 1430/3 -> 227370 = A075121(13).

Crossrefs

Cf. A068119, A073524, A075102, A075107, A075121.

Sequence in context: A281442 A256038 A050327 * A327751 A111593 A111594

Adjacent sequences: A075117 A075118 A075119 * A075121 A075122 A075123

Keyword

nonn

Author

Reinhard Zumkeller, Sep 03 2002

Extensions

More terms from Jinyuan Wang, Jan 15 2022

Status

approved