59356

Appears in sequences

• a(n) is the number of pairs of integer quadruples (b_1, b_2, b_3, b_4) and (c_1, c_2, c_3, c_4) satisfying 1 <= b_1 < b_2 < b_3 < b_4 < n, 1 <= c_1 < c_2 < c_3 < c_4 < n, b_i != c_j for all i,j = 1,2,3,4 and Product_{i=1..4} cos(2*Pi*b_i/n) = Product_{i=1..4} cos(2*Pi*c_i/n).at n=44A063780
• Even pseudoprimes to base 5.at n=4A090082
• Sum_{k=2..n} min(k,n-k)*phi(k)*(n-k).at n=37A092274
• Pseudoprimes to base 5 that are not squarefree.at n=3A243010
• Place two n-gons with radii 1 and 2 concentrically, forming an annular area between them. Connect all the vertices with line segments that lie entirely within that area. Then a(n) is the number of vertices in that figure.at n=35A337701
• G.f. satisfies A(x) = 1 + x*A(x) / (1 - x^3*A(x)^5).at n=13A365757