OFFSET
0,1
COMMENTS
Langton's Ant Superhighway, the start point (9977th iteration, J. Propp) and the period length for the Superhighway (104).
LINKS
B. D. Swan, Table of n, a(n) for n = 0..10000
C. Langton, Studying Artificial Life with Cellular Automata, Physica D: Nonlinear Phenomena, Vol. 22, 1986, pp. 120-149.
Ed Pegg Jr, 2D Turing Machines, 2004.
James Propp, Further Ant-ics, Mathematical Intelligencer, Vol. 16, 1994, pp. 37-42.
P. Sarkar, A Brief History of Cellular Automata, ACM Computing Surveys. Vol. 32, No. 1, Mar 01 2000, pp. 80-107.
S. Wolfram, 2D Turing Machines.
Index entries for linear recurrences with constant coefficients, signature (2,-1).
FORMULA
a(0)=9977, a(1)=10081, a(n) = 2*a(n-1) - a(n-2). - Harvey P. Dale, Dec 16 2011
G.f.: (9977 - 9873*x)/(1-x)^2. - Vincenzo Librandi, Sep 10 2015
E.g.f.: exp(x)*(9977 + 104*x). - Elmo R. Oliveira, Dec 08 2024
MATHEMATICA
104*Range[0, 40]+9977 (* or *) LinearRecurrence[{2, -1}, {9977, 10081}, 40] (* Harvey P. Dale, Dec 16 2011 *)
CoefficientList[Series[(9977 - 9873 x)/(1 - x)^2, {x, 0, 40}], x] (* Vincenzo Librandi, Sep 10 2015 *)
PROG
(Magma) [104*n + 9977: n in [0..40]]; // Vincenzo Librandi, Sep 10 2015
(PARI) a(n)=104*n+9977 \\ Charles R Greathouse IV, Oct 07 2015
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Robert H Barbour, Mar 20 2007, Jun 12 2007
STATUS
approved