A239913 - OEIS

A239913

a(n) = n - Q(n), where Q(n) is Hofstadter's Q-sequence A005185.

0, 1, 1, 1, 2, 2, 2, 3, 3, 4, 5, 4, 5, 6, 5, 7, 7, 7, 8, 8, 9, 10, 11, 8, 11, 12, 11, 12, 13, 14, 11, 15, 16, 14, 14, 17, 17, 16, 18, 18, 18, 19, 19, 20, 21, 22, 23, 16, 25, 25, 21, 24, 27, 24, 25, 28, 25, 28, 27, 28, 29, 30, 23, 31, 34, 28, 32, 35, 30, 30, 34, 34, 33, 35

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,5

COMMENTS

Just as for A005185, it is not known if this sequence exists for all n.

LINKS

Table of n, a(n) for n=1..74.

FORMULA

For n >= 3, a(n) = a(a(n-1)+1) + a(a(n-2)+2) - a(n-1) - a(n-2) + n - 3. - Chai Wah Wu, Apr 13 2023

PROG

(Python)

from functools import lru_cache