176214841

Appears in sequences

• Subfactorial or rencontres numbers, or derangements: number of permutations of n elements with no fixed points.at n=12A000166
• a(n) = ceiling(n!/e) with e = A001113 = exp(1).at n=12A174318
• a(0) = 1, a(n) = 1 - n * a(n-1).at n=12A182386
• Number of permutations p of [n] with no fixed points and cyclic displacement of elements restricted by nine: p(i)<>i and (i-p(i) mod n <= 9 or p(i)-i mod n <= 9).at n=12A257953
• Number of permutations p of [n] with no fixed points and cyclic displacement of elements restricted by seven: p(i)<>i and (i-p(i) mod n <= 7 or p(i)-i mod n <= 7).at n=12A260091
• Number of permutations p of [n] with no fixed points and cyclic displacement of elements restricted by six: p(i)<>i and (i-p(i) mod n <= 6 or p(i)-i mod n <= 6).at n=12A260111
• Number of permutations p of [n] with no fixed points and cyclic displacement of elements restricted by eight: p(i)<>i and (i-p(i) mod n <= 8 or p(i)-i mod n <= 8).at n=12A260115
• Number of permutations p of [n] with no fixed points and cyclic displacement of elements restricted by ten: p(i)<>i and (i-p(i) mod n <= 10 or p(i)-i mod n <= 10).at n=12A260216
• Triangle read by rows: T(n-1,k), where n >= 2 and 1 <= k <= floor(n/2), is the number of permutations of (1, 2, ..., n) having k consecutive pairs but no consecutive sequences of length greater than 2.at n=30A289632
• Number of permutations p of [2n] having no index i with |p(i)-i| = n.at n=6A306535
• Number T(n,k) of permutations p of [n] such that |p(j)-j| >= k (for all j in [n]); triangle T(n,k), n >= 0, 0 <= k <= floor(n/2), read by rows.at n=43A306543
• a(n) = A000166(floor(n/2)) if n is even otherwise A000240(floor((n + 1)/2)).at n=24A371998