21994

Appears in sequences

• Number of unlabeled Hamiltonian circuits on n-octahedron (cross polytope); also number of circular chord diagrams with n chords, modulo symmetries.at n=7A003437
• Rounded volume of a regular octahedron with edge length n.at n=36A071400
• Interprimes which are of the form s*prime, s=14.at n=31A075289
• Solutions y of the Mordell equation y^2 = x^3 - 3a^2 - 1 for a = 0,1,2, ... (solutions x are given by A053755).at n=14A173200
• Inverse Euler transform of the Riordan numbers, (A005043).at n=14A358451
• Expansion of g.f. A(x) satisfying A(x) = 1 + x * A(x)^2 * (1 + A(x)^3).at n=5A361638