10473120

Appears in sequences

• Amicable quadruples: the numbers d referred to in A036471.at n=23A036474
• Number of size 2 subsets of S_n that generate a transitive subgroup of S_n.at n=5A266910
• Triangle read by rows: T(n,k) is the number of linear chord diagrams on 2n vertices with one marked chord such that exactly k of the remaining n-1 chords are excluded by (i.e., are outside and do not contain) the marked chord.at n=43A336601