16019531

Appears in sequences

• a(n) = n*a(n-1) + (n-1)*a(n-2), a(0) = 1, a(1) = 1.at n=10A000255
• 10th differences of factorial numbers.at n=1A023047
• Numerator of Sum_{k=0..n} (-1)^k/k!.at n=12A053557
• Bisection of A000255.at n=5A100444
• Triangle read by rows: T(n,k) is the number of permutations of {1,2,...,n} having k maximal strings of increasing consecutive integers (0<=k<=floor(n/2)).at n=36A136123
• Number of permutations of {1,2,...,n} in which the fixed points and the non-fixed points alternate.at n=21A162969
• Triangle read by rows: T(n,k) is the number of permutations of [n] having no 3-sequences and having k successions (0 <= k <= floor(n/2)); a succession of a permutation p is a position i such that p(i +1) - p(i) = 1.at n=36A180185