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 A384483 #10 Aug 07 2025 07:31:33 %S A384483 0,1,2,2,3,3,4,3,4,4,5,4,5,5,5,4,5,5,6,5,5,5,6,5,5,5,5,6,6,6,5,5,6,6, %T A384483 6,5,6,6,6,6,6,6,6,6,6,5,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,5,6,6,6,6, %U A384483 6,7,6,6,6,6,6,6,7,6,7,6,5,6,6,6,6,6,7 %N A384483 Length of shortest addition-composition chain for n, starting with 1 and x. %C A384483 See A384480 for the definition of addition-composition chains. The number n is identified with the constant function f(x) = n. %F A384483 a(n) <= A003313(n). %F A384483 a(n) <= a(n-1) + 1. %e A384483 The smallest n for which a(n) < A003313(n) is n = 21. The length of a shortest addition chain for 21 is A003313(21) = 6, but there are addition-composition chains of length 5, for example (1, x,) x+1, 2*x+2, 3*x+3, 6, 21. 6 and 21 are the compositions of 3*x+3 with 1 and 6, respectively. %Y A384483 Row 0 of A384480 for columns k >= 1. %Y A384483 Cf. A003313 (addition only), A230697 (addition and multiplication), A384384 (addition, multiplication, and composition), A384484, A384485. %K A384483 nonn %O A384483 1,3 %A A384483 _Pontus von Brömssen_, Jun 02 2025