55650

Appears in sequences

• Rencontres numbers: number of permutations of [n] with exactly 4 fixed points.at n=6A000475
• Triangle T(n,k) of rencontres numbers (number of permutations of n elements with k fixed points).at n=59A008290
• Triangle of rencontres numbers.at n=40A008291
• Coordination sequence for D_7 lattice.at n=4A008359
• Schoenheim bound L_1(n,n-5,n-6).at n=27A036837
• 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=61A098825
• Square array T(n,k) read by antidiagonals: coordination sequence for lattice D_n.at n=32A103903
• a(n) = (binomial(n,5) - floor(n/5)) / 5.at n=28A215052
• The number of P-positions in the game of Nim with up to five piles, allowing for piles of zero, such that the total number of objects in all piles is 2n.at n=33A238759
• Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 473", based on the 5-celled von Neumann neighborhood.at n=42A272425
• Column 8 of A286781.at n=2A286793
• Number of maximal subsets of {1..n} of which every subset has a different sum.at n=33A325865
• a(n) is the least number k such that there are exactly n pairs (p,q) of primes with p<q such that p+q = 2*k and that 2*k+p, 2*k+q, p*q-2*k and p*q+2*k are primes.at n=28A354462