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 A283765 #9 Mar 17 2017 22:02:53
%S A283765 3,4,5,8,9,10,14,15,19,20,24,25,26,29,30,31,35,36,40,41,45,46,47,50,
%T A283765 51,52,55,56,57,61,62,66,67,68,71,72,73,76,77,78,82,83,87,88,89,92,93,
%U A283765 94,97,98,99,103,104,108,109,113,114,115,118,119,120,124,125
%N A283765 Numbers k such that L(k) is even, where L = A000201 = lower Wythoff sequence.
%C A283765 Complement of A283766.
%H A283765 Clark Kimberling, <a href="/A283765/b283765.txt">Table of n, a(n) for n = 1..10000</a>
%F A283765 a(n+1) - a(n) is in {1,3,4} for every n.
%t A283765 r = GoldenRatio; z = 250; t = Table[Floor[n*r], {n, 1, z}]; u = Mod[t, 2];
%t A283765 Flatten[Position[u, 0]] (* A283765 *)
%t A283765 Flatten[Position[u, 1]] (* A283766 *)
%o A283765 (Scheme, with Antti Karttunen's IntSeq-library)
%o A283765 (define A283765 (MATCHING-POS 1 1 (lambda (n) (even? (A105774 n)))))
%o A283765 ;; _Antti Karttunen_, Mar 17 2017
%Y A283765 Cf. A000201, A001622, A105774, A283766, A283767.
%K A283765 nonn,easy
%O A283765 1,1
%A A283765 _Clark Kimberling_, Mar 17 2017