57905114

Appears in sequences

• a(n) = Sum_{i=0..n} (n!/(n-i)!)^2.at n=7A006040
• a(2n-1) = n*a(2n-2), a(2n) = n*a(2n-1) + 1.at n=13A007876
• T(n,k)=Number of nXk array permutations with each element remaining in its original row or its original column.at n=29A188808
• T(n,k)=Number of nXk array permutations with each element remaining in its original row or its original column.at n=34A188808
• Square array T(n,k), n >= 0, k >= 0, read by antidiagonals, where T(n,k) = (n!)^k * Sum_{j=1..n} (1/j!)^k.at n=52A343863
• Interleaving A006040 and A228229.at n=13A375231