OFFSET
0,7
COMMENTS
After the initial 0 the sequence is periodic with period 10.
This game is called "Guiles" in Winning Ways.
REFERENCES
E. R. Berlekamp, J. H. Conway and R. K. Guy, Winning Ways, Academic Press, NY, 2 vols., 1982; see Chapter 4, p. 104.
LINKS
Colin Barker, Table of n, a(n) for n = 0..1000
R. K. Guy and C. A. B. Smith, The G-values of various games, Proc. Cambridge Philos. Soc. 52 (1956), 514-526. See Table 2.
Index entries for linear recurrences with constant coefficients, signature (0, 0, 0, 0, 0, 0, 0, 0, 0, 1).
FORMULA
From Colin Barker, Apr 02 2019: (Start)
G.f.: x*(1 + x + x^3 + x^4 + 2*x^5 + 2*x^6 + x^7 + 2*x^8 + 2*x^9) / ((1 - x)*(1 + x)*(1 - x + x^2 - x^3 + x^4)*(1 + x + x^2 + x^3 + x^4)).
a(n) = a(n-10) for n>10.
(End)
MATHEMATICA
LinearRecurrence[{0, 0, 0, 0, 0, 0, 0, 0, 0, 1}, {0, 1, 1, 0, 1, 1, 2, 2, 1, 2, 2}, 100] (* Ray Chandler, Aug 26 2015; offset 0 corrected by Georg Fischer, Apr 02 2019 *)
PROG
(PARI) concat(0, Vec(x*(1 + x + x^3 + x^4 + 2*x^5 + 2*x^6 + x^7 + 2*x^8 + 2*x^9) / ((1 - x)*(1 + x)*(1 - x + x^2 - x^3 + x^4)*(1 + x + x^2 + x^3 + x^4)) + O(x^80))) \\ Colin Barker, Apr 02 2019
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Richard Sabey, Jan 24 2007
EXTENSIONS
Extended by Ray Chandler, Aug 26 2015
Added initial 0 and changed offset. - N. J. A. Sloane, Jul 02 2016
STATUS
approved