OFFSET
1,8
LINKS
T. D. Noe, Table of n, a(n) for n=1..10000
Kevin O'Bryant, Bruce Reznick and Monika Serbinowska, Almost alternating sums, arXiv:math/0308087 [math.NT], 2003-2005.
Kevin O'Bryant, Bruce Reznick and Monika Serbinowska, Almost alternating sums, Amer. Math. Monthly, Vol. 113 (October 2006), 673-688.
MATHEMATICA
Rest[FoldList[Plus, 0, (-1)^Floor[Pi*Range[120]]]]
PROG
(PARI) vector(130, n, sum(j=1, n, (-1)^(j\(1/Pi))) ) \\ G. C. Greubel, Sep 05 2019
(Magma) R:= RealField(20); [&+[(-1)^Floor(j*Pi(R)): j in [1..n]]: n in [1..130]]; // G. C. Greubel, Sep 05 2019
(Sage) [sum((-1)^floor(j*pi) for j in (1..n)) for n in (1..130)] # G. C. Greubel, Sep 05 2019
CROSSREFS
KEYWORD
easy,sign
AUTHOR
T. D. Noe, Oct 11 2006
STATUS
approved