The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 A274369 Let the starting square of Langton's ant have coordinates (0, 0), with the ant looking in negative x-direction. a(n) is the x-coordinate of the ant after n moves. 4
 0, 0, 1, 1, 0, 0, -1, -1, 0, 0, 1, 1, 0, 0, 1, 1, 0, 0, 1, 1, 2, 2, 1, 1, 2, 2, 3, 3, 2, 2, 1, 1, 2, 2, 3, 3, 4, 4, 3, 3, 2, 2, 3, 3, 2, 2, 3, 3, 2, 2, 1, 1, 0, 0, -1, -1, 0, 0, -1, -1, 0, 0, -1, -1, -2, -2, -1, -1, -2, -2, -3, -3, -2, -2, -1, -1, -2, -2, -3 (list; graph; refs; listen; history; text; internal format)
 OFFSET 0,21 LINKS Rémy Sigrist, Table of n, a(n) for n = 0..15000 Felix Fröhlich, Coordinates of Langton's ant. Wikipedia, Langton's ant. FORMULA a(n+104) = a(n) + 2 for n > 9975. - Andrey Zabolotskiy, Jul 05 2016 PROG (Python) # A274369: Langton's ant by Andrey Zabolotskiy, Jul 05 2016 def ant(n):     steps = [(1, 0), (0, 1), (-1, 0), (0, -1)]     black = set()     x = y = 0     position = [(x, y)]     direction = 2     for _ in range(n):         if (x, y) in black:             black.remove((x, y))             direction += 1         else:             black.add((x, y))             direction -= 1         (dx, dy) = steps[direction%4]         x += dx         y += dy         position.append((x, y))     return position print ([p[0] for p in ant(100)]) # change p[0] to p[1] to get y-coordinates CROSSREFS Cf. A274370 (y-coordinate). Cf. A102358, A102369, A204810, A255938, A261990, A269757. Sequence in context: A165123 A318439 A106180 * A055091 A014678 A164516 Adjacent sequences:  A274366 A274367 A274368 * A274370 A274371 A274372 KEYWORD sign,look AUTHOR Felix Fröhlich, Jun 19 2016 STATUS approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

Last modified January 25 01:49 EST 2020. Contains 331229 sequences. (Running on oeis4.)