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 A328653 #4 Oct 25 2019 13:05:08 %S A328653 1,3,7,18,35,84,222,459,1186,2099,4731,8093,19674,49289,102408,242522, %T A328653 659653 %N A328653 a(0) = 1, and for n >= 0, a(n+1) = -A326936(a(n)). %C A328653 This sequence gives the values of the ancestors of the node with value 1 in the binary tree described in sequence A326936. %Y A328653 Cf. A326936. %K A328653 nonn,more %O A328653 0,2 %A A328653 _Rémy Sigrist_, Oct 24 2019