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 A334486 #18 Feb 07 2021 09:51:30 %S A334486 0,0,1,1,2,2,2,1,1,2,3,3,2,3,4,5,5,5,4,4,3,3,4,4,3,2,3,4,5,5,6,6,7,7, %T A334486 7,6,6,7,7,8,8,8,7,6,5,4,5,6,6,5,5,6,6,7,7,7,6,6,7,8,8,7,8,9,9,10,11, %U A334486 11,10,11,12,13,13,13,12,12,11,11,10,9,10,10 %N A334486 a(n) is the Y-coordinate of the n-th point of Gosper's flowsnake curve; sequence A334485 gives X-coordinates. %C A334486 Coordinates are given on a hexagonal lattice with X-axis and Y-axis as follows: %C A334486 Y %C A334486 / %C A334486 / %C A334486 0 ---- X %H A334486 Rémy Sigrist, <a href="/A334486/b334486.txt">Table of n, a(n) for n = 0..2401</a> %H A334486 Rémy Sigrist, <a href="/A334486/a334486.gp.txt">PARI program for A334486</a> %H A334486 Wikipedia, <a href="https://en.wikipedia.org/wiki/Gosper_curve">Gosper curve</a> %H A334486 <a href="/index/Con#coordinates_2D_curves">Index entries for sequences related to coordinates of 2D curves</a> %e A334486 The Gosper curve starts (on a hexagonal lattice) as follows: %e A334486 . . . . . +---+---+ . . . . %e A334486 \ \ %e A334486 . . +---+---+ +---+ + . . . . %e A334486 \ \ / / %e A334486 . . . +---+ +---+ + +---+ . . %e A334486 / \ \ \ %e A334486 . . +---+ +---+---+ + + + . . %e A334486 / \ \ \ / 49 %e A334486 . . + +---+ +---+ + + . . . %e A334486 \ \ \ / / %e A334486 . . + + +---+ + +---+ . . . %e A334486 \ / \ / /10 %e A334486 . . . + +---+---+ + + . . . %e A334486 25 \ \ /9 %e A334486 . . . . +---+ +---+ . . . . %e A334486 / 7 8 %e A334486 . . . . +---+ . . . . . . %e A334486 0 1 %e A334486 - hence a(2) = a(3) = a(7) = a(8) = 1. %o A334486 (PARI) See Links section. %Y A334486 Cf. A334485 (X coordinate), A229214 (direction +-1,2,3), A261180 (direction 0..5). %K A334486 nonn %O A334486 0,5 %A A334486 _Rémy Sigrist_, May 03 2020