%I #18 Feb 07 2021 09:51:30
%S 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 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 11,10,11,12,13,13,13,12,12,11,11,10,9,10,10
%N a(n) is the Y-coordinate of the n-th point of Gosper's flowsnake curve; sequence A334485 gives X-coordinates.
%C Coordinates are given on a hexagonal lattice with X-axis and Y-axis as follows:
%C Y
%C /
%C /
%C 0 ---- X
%H Rémy Sigrist, <a href="/A334486/b334486.txt">Table of n, a(n) for n = 0..2401</a>
%H Rémy Sigrist, <a href="/A334486/a334486.gp.txt">PARI program for A334486</a>
%H Wikipedia, <a href="https://en.wikipedia.org/wiki/Gosper_curve">Gosper curve</a>
%H <a href="/index/Con#coordinates_2D_curves">Index entries for sequences related to coordinates of 2D curves</a>
%e The Gosper curve starts (on a hexagonal lattice) as follows:
%e . . . . . +---+---+ . . . .
%e \ \
%e . . +---+---+ +---+ + . . . .
%e \ \ / /
%e . . . +---+ +---+ + +---+ . .
%e / \ \ \
%e . . +---+ +---+---+ + + + . .
%e / \ \ \ / 49
%e . . + +---+ +---+ + + . . .
%e \ \ \ / /
%e . . + + +---+ + +---+ . . .
%e \ / \ / /10
%e . . . + +---+---+ + + . . .
%e 25 \ \ /9
%e . . . . +---+ +---+ . . . .
%e / 7 8
%e . . . . +---+ . . . . . .
%e 0 1
%e - hence a(2) = a(3) = a(7) = a(8) = 1.
%o (PARI) See Links section.
%Y Cf. A334485 (X coordinate), A229214 (direction +-1,2,3), A261180 (direction 0..5).
%K nonn
%O 0,5
%A _Rémy Sigrist_, May 03 2020