A364528 Number of 1's required to build -n using +, -, *, and parentheses.

3, 4, 5, 6, 6, 7, 7, 7, 8, 8, 8, 9, 9, 9, 9, 9, 9, 10, 10, 10, 10, 10, 10, 10, 11, 10, 11, 11, 11, 11, 11, 11, 11, 11, 11, 12, 12, 12, 12, 12, 12, 12, 13, 12, 12, 12, 12, 12, 13, 13, 12, 12, 12, 13, 13, 13, 13, 13, 13, 13, 14, 13, 13, 13, 14, 13, 14, 13, 13

Offset: 1

Author

Pontus von Brömssen, Jul 27 2023

Keywords

• nonn

Comments

Unary minus is not allowed, otherwise we would have a(n) = A091333(n).

Examples

			a(5) = 6 because -5 = 1 - (1+1) * (1+1+1).
a(10) = 8 because -10 = 2 * (-5) = (1+1) * (1 - (1+1) * (1+1+1)).
		

Links

• Index to sequences related to the complexity of n.

Crossrefs

Cf. A091333.

Formula

A091333(n) <= a(n) <= 1 + A091333(n+1) <= 2 + A091333(n). Equality holds in the first inequality for n = 11, 17, 22, 23, 26, 29, ... .