234061

Appears in sequences

• Array (a frieze pattern) defined by a(n,k) = (a(n-1,k)*a(n-1,k+1) - 1) / a(n-2,k+1), read by antidiagonals.at n=53A007754
• a(n) = n*a(n-1) - a(n-2) with a(0) = 0, a(1) = 1.at n=9A058798
• Triangle read by rows: T(n,k) = number of permutations p of [n] such that max(|p(i)-i|)=k (n>=1, 0<=k<=n-1).at n=50A130152
• a(0) = 1, a(1) = 2; for k>0, a(2*k) = k*a(2*k-1) + a(2*k-2), a(2*k+1) = a(2*k) + a(2*k-1).at n=15A273939
• Number of permutations p of [n] such that max_{j=1..n} |p(j)-j| = 5.at n=5A323801
• Number of permutations p of [n] such that max_{j=1..n} |p(j)-j| = floor(n/2).at n=9A323807