A386910 Number of iterations of seven segments count x -> A063720(x) to go from n to a fixed point.

2, 2, 1, 1, 0, 0, 1, 2, 3, 1, 4, 1, 3, 3, 2, 3, 3, 1, 2, 3, 2, 3, 5, 5, 2, 5, 5, 4, 4, 5, 2, 3, 5, 5, 2, 5, 5, 4, 4, 5, 5, 2, 2, 2, 4, 2, 2, 3, 2, 2, 2, 3, 5, 5, 2, 5, 5, 4, 4, 5, 2, 3, 5, 5, 2, 5, 5, 4, 4, 5, 2, 1, 4, 4, 3, 4, 4, 2, 5, 4, 4, 2, 4, 4, 2, 4, 4

Offset

0,1

Comments

A063720 is a strictly decreasing function A063720(x) < x whenever x >= 10 and all single digit x reach a fixed point A063720(x) = x with x in {4, 5}.

This sequence is unbounded and the first occurrence of a(n) = k is at n = A338255(k + 1) for any k >= 3.

Links

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

Example

For n = 12, the a(12) = 3 steps are 12 -> 7 -> 3 -> 5 segments, and 5 is a fixed point A063720(5) = 5.

Crossrefs

Cf. A063720, A328330, A338255, A385249.

Cf. A006942, A010371, A074458, A277116 (segments variation).

Sequence in context: A359216 A274370 A128521 * A090477 A349802 A368753

Adjacent sequences: A386907 A386908 A386909 * A386911 A386912 A386913

Keyword

nonn,base,easy

Author

Marco Ripà, Aug 07 2025

Status

approved