A385249 Number of iterations of seven segments count x -> A010371(x) to go from n to a fixed point.

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

Offset

0,2

Comments

A010371 is a strictly decreasing function A010371(x) < x whenever x >= 10 and all single digit x reach a fixed point A010371(x) = x with x in {4, 5, 6}.

This sequence is unbounded.

Links

Table of n, a(n) for n=0..86.

Example

For n = 12, the a(12) = 2 steps are 12 -> 7 -> 4 segments, and 4 is a fixed point A010371(4) = 4.

Crossrefs

Cf. A010371.

Cf. A328330 (segments variation).

Sequence in context: A225230 A367106 A387106 * A328084 A351357 A263250

Adjacent sequences: A385246 A385247 A385248 * A385250 A385251 A385252

Keyword

nonn,base,easy

Author

Marco Ripà, Jul 28 2025

Status

approved