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 A362756 #6 May 02 2023 12:03:00 %S A362756 0,0,1,1,1,2,1,1,1,2,2,2,3,2,2,2,2,1,1,1,2,2,2,3,2,2,2,3,3,3,4,3,3,3, %T A362756 3,2,2,2,3,3,3,3,2,2,2,2,1,1,1,2,2,2,3,2,2,2,3,3,3,4,3,3,3,3,2,2,2,3, %U A362756 3,3,4,3,3,3,4,4,4,5,4,4,4,4,3,3,3,4,4 %N A362756 Sum of the bits of the "fractional part" of the base-phi representation of n. %C A362756 The phi-representation of n is the (essentially) unique way to write n = Sum_{j=L..R} b(j)*phi^j, where b(j) is in {0,1} and -oo < L <= 0 <= R, where phi = (1+sqrt(5))/2, subject to the condition that b(j)b(j+1) != 1. The "fractional" part is the string of bits b(L)...b(-1). %C A362756 The first difference of a(n) is Fibonacci-automatic and takes values in {-1,0,1} only. %H A362756 George Bergman, <a href="https://math.berkeley.edu/~gbergman/papers/base_tau.pdf">A number system with an irrational base</a>, Math. Mag. 31 (1957), 98-110. %F A362756 There is a linear representation of rank 21 for a(n). %e A362756 For n = 20 the phi-representation is 1000010.010001, so a(20) = 2. %Y A362756 Cf. A055778, A362716. %K A362756 nonn %O A362756 0,6 %A A362756 _Jeffrey Shallit_, May 02 2023