141876

Appears in sequences

• Number of permutations of [n] with 3 cycle lengths.at n=3A133119
• Triangular array read by rows: T(n,k) is the number of n-permutations that have exactly k distinct cycle lengths.at n=19A218868
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals downwards, where T(n,0) = 0^n and T(n,k) = k * Sum_{r=0..n} binomial(n,r) * binomial(3*n+3*r+k,n)/(3*n+3*r+k) for k > 0.at n=33A378240
• G.f. A(x) satisfies A(x) = ( (1 + x*A(x)^3)/(1 - x*A(x)) )^2.at n=5A379244