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

Author

Marco Ripà, Jul 28 2025

Keywords

• nonn
• base
• easy

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 and the first occurrence of a(n) = k is at n = A385250(k).

Examples

			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, A385250.

Cf. A328330 (segments variation).