31904

Appears in sequences

• Numbers k such that the continued fraction for sqrt(k) has even period and if the last term of the periodic part is deleted the central term is 89.at n=40A031587
• Square array T(n,k), n >= 2, k >= 2, read by antidiagonals, where T(n,k) is the number of (undirected) Hamiltonian cycles on the n X k king graph.at n=22A339190
• Square array T(n,k), n >= 2, k >= 2, read by antidiagonals, where T(n,k) is the number of (undirected) Hamiltonian cycles on the n X k king graph.at n=26A339190
• Number of (undirected) Hamiltonian cycles on the n X 3 king graph.at n=5A339200
• a(n) = Sum_{k=0..floor(n/2)} 2^k * binomial(k,n-2*k)^2.at n=15A387476