cp's OEIS Frontend

A164846 Triangle read by rows: frequency with which the number of values taken by cos(2*Pi/k) mod j occurs for each j >= 1, taken over k = 1..j-1.

%I A164846 #12 Jan 18 2024 07:49:04
%S A164846 0,0,1,0,1,1,0,2,1,0,0,1,3,0,0,0,3,0,0,1,1,0,2,3,0,1,0,0,0,4,0,0,2,0,
%T A164846 0,1,0,3,1,1,2,0,1,0,0,0,3,2,0,1,2,0,0,1,0,0,2,5,1,1,0,1,0,0,0,0,0,6,
%U A164846 0,0,3,0,0,0,0,0,0,2,0,3,6,0,2,0,1,0,0,0,0,0,0,0,5,2,0,2,1,0,0,1,2,0,0,0,0
%N A164846 Triangle read by rows: frequency with which the number of values taken by cos(2*Pi/k) mod j occurs for each j >= 1, taken over k = 1..j-1.
%C A164846 See A164823 for explanatory comment and the definition of "cos(x) mod j".
%H A164846 Christopher Hunt Gribble, <a href="/A164846/b164846.txt">Flattened triangle, for j = 1..100 and k = 1..j-1</a>.
%e A164846 The triangle of numbers is:
%e A164846 ..j....Frequency of numbers of solutions over k
%e A164846 .......0..1..2..3..4..5..6..7..8..9..10
%e A164846 ..1....0
%e A164846 ..2....0..1
%e A164846 ..3....0..1..1
%e A164846 ..4....0..2..1..0
%e A164846 ..5....0..1..3..0..0
%e A164846 ..6....0..3..0..0..1..1
%e A164846 ..7....0..2..3..0..1..0..0
%e A164846 ..8....0..4..0..0..2..0..0..1
%e A164846 ..9....0..3..1..1..2..0..1..0..0
%e A164846 .10....0..3..2..0..1..2..0..0..1..0
%e A164846 .11....0..2..5..1..1..0..1..0..0..0..0
%Y A164846 Cf. A164822, A164823, A164831, A165252.
%K A164846 nonn,tabl
%O A164846 1,8
%A A164846 _Christopher Hunt Gribble_, Aug 28 2009
%E A164846 Minor edits from _N. J. A. Sloane_, Sep 01 2009
%E A164846 Sequence corrected by _Christopher Hunt Gribble_, Sep 10 2009
%E A164846 Minor edits by _Christopher Hunt Gribble_, Oct 01 2009