OFFSET
0,8
COMMENTS
The cyclic pattern (and numerator of the gf) is computed using Euclid's algorithm for GCD.
REFERENCES
R. L. Graham, D. E. Knuth and O. Patashnik, Concrete Mathematics, Addison-Wesley, NY, 1994.
N. Dershowitz and E. M. Reingold, Calendrical Calculations, Cambridge University Press, 1997.
LINKS
G. C. Greubel, Table of n, a(n) for n = 0..5000
N. Dershowitz and E. M. Reingold, Calendrical Calculations Web Site.
Index entries for linear recurrences with constant coefficients, signature (1,0,0,0,0,0,1,-1).
FORMULA
G.f.: x^4*(1+x)*(x^2-x+1)/( (x^6+x^5+x^4+x^3+x^2+x+1)*(x-1)^2 ). - Numerator corrected by R. J. Mathar, Feb 20 2011
Sum_{n>=4} (-1)^n/a(n) = Pi/4 (A003881). - Amiram Eldar, Sep 30 2022
MATHEMATICA
Table[Floor[2*n/7], {n, 0, 50}] (* G. C. Greubel, Nov 03 2017 *)
PROG
(PARI) a(n)=2*n\7 \\ Charles R Greathouse IV, Sep 24 2015
(Magma) [Floor(2*n/7): n in [0..50]]; // G. C. Greubel, Nov 03 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved