A057356 a(n) = floor(2*n/7).
0, 0, 0, 0, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 6, 6, 6, 6, 7, 7, 7, 8, 8, 8, 8, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 12, 12, 12, 12, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 16, 16, 16, 16, 17, 17, 17, 18, 18, 18, 18, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 22, 22, 22
Offset: 0
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).
Crossrefs
Programs
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Magma
[Floor(2*n/7): n in [0..50]]; // G. C. Greubel, Nov 03 2017
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Mathematica
Table[Floor[2*n/7], {n,0,50}] (* G. C. Greubel, Nov 03 2017 *) -
PARI
a(n)=2*n\7 \\ Charles R Greathouse IV, Sep 24 2015
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
Comments