536900

Appears in sequences

• Triangle read by rows: T(n,k) is the number of permutations p of {1,2,...,n} such that the set {p(i)-i, i=1,2,...,n} has exactly k elements (1<=k<=n).at n=50A125182
• The Wiener index of a link of n fullerenes C_{20} (see the Ghorbani and Hosseinzadeh reference).at n=12A216114