66744

Appears in sequences

• Rencontres numbers: number of permutations of [n] with exactly two fixed points.at n=9A000387
• Triangle T(n,k) of rencontres numbers (number of permutations of n elements with k fixed points).at n=47A008290
• Triangle of rencontres numbers.at n=30A008291
• 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=52A098825
• T(n,k) is the number of partial bijections (or subpermutations) of an n-element set of height k (height(alpha) = |Im(alpha)|) and with exactly 2 fixed points.at n=35A144091
• Duplicate of A000387.at n=9A145221
• Triangle read by rows: T(n,k) is the number of odd permutations (of an n-set) with exactly k fixed points.at n=45A145225
• Number of derangements on n elements with an even number of cycles.at n=9A216778
• T(n,k)=Number of (n+1)X(k+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally or antidiagonally, with no adjacent elements equal.at n=47A232589
• Number of (3+1)X(n+1) 0..2 arrays with every element next to itself plus and minus one within the range 0..2 horizontally or antidiagonally, with no adjacent elements equal.at n=7A232592
• T(n, k) = binomial(n, k)*sf(n-k)*sf(k) where sf is the subfactorial (A000166). Triangle read by rows, for 0 <= k <= n.at n=47A337615
• T(n, k) = binomial(n, k)*sf(n-k)*sf(k) where sf is the subfactorial (A000166). Triangle read by rows, for 0 <= k <= n.at n=52A337615
• Triangle T(n,k) for the number of permutations in symmetric group S_n with (n-k) fixed points and an even number of non-fixed point cycles. Equivalent to the number of cycles of n items with cycle type defined by non-unity partitions of k<=n that contain an even number of parts.at n=54A373417
• Triangle read by rows: T(n,k) = number of permutations in symmetric group S_n with an even number of non-fixed point cycles, without k<=n particular fixed points.at n=54A374419
• Numbers k such that k and k+1 are both terms in A377209.at n=23A377271