280120

Appears in sequences

• Denominators of continued fraction convergents to sqrt(995).at n=11A042927
• Number of sequences of length n with elements {-2,-1,+1,+2}, 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 (directed) circuits on the circulant graph C_n(1,2).at n=30A137725
• E.g.f.: -1/((1-LambertW(-x))*(1+x)).at n=8A277508
• Triangle read by rows: T(n,k) is the number of rooted toroidal maps with n edges and k faces and without isthmuses, n >= 2, k = 1..n-1.at n=30A343092
• Irregular triangle read by rows: T(n,k) is the number of chordless cycles of length k in the n-diagonal intersection graph, 4 <= k <= kmax.at n=60A371340