20151433

Appears in sequences

• Number of sequences of length n with elements {-2,-1,+1,+2}, counted up to simultaneous reversal and negation, such that the sum of elements of the whole sequence but of no proper subsequence equals 0 modulo n. For n>=4, the number of Hamiltonian (undirected) cycles on the circulant graph C_n(1,2).at n=43A137726
• Number of (undirected) Hamiltonian cycles in the n-antiprism graph.at n=21A306447