169632

Appears in sequences

• a(n) = n*(n-1)*(n^2 + 2)/6.at n=32A071244
• The work performed by a partial function f:{1,...,n}->{1,...,n} is defined to be work(f)=sum(|i-f(i)|,i in dom(f)); a(n) is equal to sum(work(f)) where the sum is over all order-preserving partial functions f:{1,...,n}->{1,...,n}.at n=6A111903
• Number of length 2+2 0..n arrays with no three consecutive terms having the sum of any two elements equal to twice the third.at n=19A248463
• The number of permutations of length n sortable by 3 block interchanges.at n=8A256181
• Dirichlet g.f.: (zeta(s-3) / zeta(s))^2.at n=34A338165