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a(n) is the number of values taken by cos(2*Pi/k) mod n for all k in 1..n-1.
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%I #13 Jan 18 2024 07:46:36

%S 0,1,3,4,7,12,12,19,22,29,25,40,29,48,59,85,42,83,53,93,99,96,64,175,

%T 144,113,159,161,97,235,100,297,187,165,231,274,111,200,224,386,156,

%U 398,149,303,425,248,152,733,450,513,332,359,181,572,448,648,384,361,221,786

%N a(n) is the number of values taken by cos(2*Pi/k) mod n for all k in 1..n-1.

%C See A164823 for explanatory comment and the definition of "cos(x) mod j".

%H Christopher Hunt Gribble, <a href="/A164831/b164831.txt">Table of n, a(n) for n = 1..1000</a>.

%Y Cf. A164822, A164823, A164846, A165252.

%K nonn

%O 1,3

%A _Christopher Hunt Gribble_, Aug 27 2009

%E Edited by _N. J. A. Sloane_, Sep 01 2009

%E Sequence corrected by _Christopher Hunt Gribble_, Sep 10 2009