This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A364528 #7 Jul 29 2023 05:07:17 %S A364528 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, %T A364528 11,11,11,11,11,11,11,12,12,12,12,12,12,12,13,12,12,12,12,12,13,13,12, %U A364528 12,12,13,13,13,13,13,13,13,14,13,13,13,14,13,14,13,13 %N A364528 Number of 1's required to build -n using +, -, *, and parentheses. %C A364528 Unary minus is not allowed, otherwise we would have a(n) = A091333(n). %H A364528 <a href="/index/Com#complexity">Index to sequences related to the complexity of n</a>. %F A364528 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, ... . %e A364528 a(5) = 6 because -5 = 1 - (1+1) * (1+1+1). %e A364528 a(10) = 8 because -10 = 2 * (-5) = (1+1) * (1 - (1+1) * (1+1+1)). %Y A364528 Cf. A091333. %K A364528 nonn %O A364528 1,1 %A A364528 _Pontus von Brömssen_, Jul 27 2023