234237

Appears in sequences

• Number of even non-cototients not exceeding 2^n.at n=20A072297
• Number of length 4 arrays x(i), i=1..4 with x(i) in i..i+n and no value appearing more than 3 times.at n=20A250362
• a(n) = (-cos(Pi/7)/cos(2*Pi/7))^n + (-cos(2*Pi/7)/cos(3*Pi/7))^n + (cos(3*Pi/7)/cos(Pi/7))^n.at n=12A274220