1334960

Appears in sequences

• Rencontres numbers: number of permutations of [n] with exactly one fixed point.at n=9A000240
• Triangle T(n,k) of rencontres numbers (number of permutations of n elements with k fixed points).at n=56A008290
• Triangle of rencontres numbers.at n=37A008291
• a(n) = floor( n! / e ).at n=9A014508
• Table T(n,k) giving number of ways of obtaining exactly one correct answer on an (n,k)-matching problem (1 <= k <= n).at n=54A076732
• Triangle read by rows: T(n,k) = number of partial derangements, that is, the number of permutations of n distinct, ordered items in which exactly k of the items are in their natural ordered positions, for n >= 0, k = n, n-1, ..., 1, 0.at n=64A098825
• Triangle read by rows: T(n,k) is the number of non-derangements of {1,2,...,n} for which the difference between the largest and smallest fixed points is k (n>=1; 0 <= k <= n-1).at n=45A161129
• Triangle read by rows: T(n,k) is the number of permutations of [n] starting with 1, 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=37A180186
• Triangle read by rows: T(n,k) is the number of permutations of [n] with k circular successions (0<=k<=n-1). A circular succession in a permutation p of [n] is either a pair p(i), p(i+1), where p(i+1)=p(i)+1 or the pair p(n), p(1) if p(1)=p(n)+1.at n=45A180188
• a(0)=0, a(n) = (a(n-1) * n) XOR n.at n=10A182390
• Triangle read by rows: T(n,k) = number of permutations of [n] having exactly one adjacent k-cycle. (n>=1, 1<=k<=n).at n=45A370527
• a(n) = A000166(floor(n/2)) if n is even otherwise A000240(floor((n + 1)/2)).at n=19A371998