116775

Appears in sequences

• a(n) = 2*a(n-1) - a(n-2) - a(n-4) with a(0) = a(1) = 0, a(2) = 1, a(3) = 2.at n=34A014292
• G.f.: imaginary part of 1/(1 - i*x - i*x^2) where i=sqrt(-1).at n=34A201838
• Number of all polyhedra (tetrahedra of any orientation and octahedra) of any size, formed when intersecting a regular tetrahedron by planes parallel to its sides and dividing its edges into n equal parts.at n=33A216175
• Expansion of 1/(2 - Product_{k>=1} (1 + x^(2*k-1))).at n=22A307058
• Expansion of 1/(2 - Product_{k>=1} 1/(1 + x^k)).at n=22A307060