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A115789
a(n) = (floor((n+1)*Pi) - floor(n*Pi)) mod 2.
4
1, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 1, 1, 1, 1, 0
OFFSET
0,1
COMMENTS
The arithmetic mean (1/(n+1))*Sum_{k=0..n} a(k) converges to 4 - Pi. What is effectively the same: the Cesaro limit (C1) of a(n) is 4 - Pi.
LINKS
FORMULA
a(n) = (floor((n+1)*Pi) - floor(n*Pi)) mod 2.
a(n) = A063438(n) mod 2.
a(n) = 1 - A115790(n).
EXAMPLE
a(6)=1 because 7*Pi=21.99..., 6*Pi=18.84... and so a(6) = (21 - 18) mod 2 = 1;
a(7)=0 because 8*Pi=25.13... and so a(7) = (25 - 21) mod 2 = 0.
MATHEMATICA
Mod[Differences[Floor[Pi*Range[0, 120]]], 2] (* Paolo Xausa, Nov 07 2025 *)
CROSSREFS
KEYWORD
nonn,less
AUTHOR
Hieronymus Fischer, Jan 31 2006
STATUS
approved