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 A181108 #8 Sep 04 2021 08:25:41 %S A181108 1,2,1,3,3,1,4,4,3,1,5,6,4,3,1,6,8,5,4,3,1,7,9,7,5,4,3,1,8,11,9,7,5,4, %T A181108 3,1,9,12,10,9,7,5,4,3,1,10,14,12,11,9,7,5,4,3,1,11,16,14,12,11,9,7,5, %U A181108 4,3,1,12,17,16,13,12,11,9,7,5,4,3,1,13,19,17,15,13,12,11,9,7,5,4,3,1,14,21 %N A181108 Array whose rows result from iterating an algorithm that carries the natural numbers to the lower Wythoff sequence. %C A181108 Row 1: A000027 (natural numbers). %C A181108 Row 2: A000201 (lower Wythoff sequence). %C A181108 Limit-row: A003159. %F A181108 To generate row n+1 from row n, let %F A181108 (row n) = (s(1), s(2), s(3), ...) %F A181108 (row n+1) = (t(1), t(2), t(3), ...) %F A181108 Then for k=1,2,3,..., let %F A181108 t(k) = least positive integer not yet in sequences t or u %F A181108 u(k) = t(k) + s(k). %e A181108 Northwest corner: %e A181108 1...2...3...4...5...6...7....8....9... %e A181108 1...3...4...6...8...9...11...12...14... %e A181108 1...3...4...5...7...9...10...12...14... %e A181108 1...3...4...5...7...9...11...12...13... %e A181108 To get row 2 from row 1: %e A181108 s: 1...2...3...4...5....6....7... %e A181108 t: 1...3...4...6...8....9....11... %e A181108 u: 2...5...7...10..13...15...18... %e A181108 To get row 3 from row 2: %e A181108 s: 1...3...4...6....8....9....11 %e A181108 t: 1...3...4...5....7....9....10 %e A181108 u: 2...6...8...11...15...18...21 %Y A181108 Cf. A000201, A003159, A181109. %K A181108 nonn,tabl %O A181108 1,2 %A A181108 _Clark Kimberling_, Oct 03 2010