925705

Appears in sequences

• Number of multiset permutations of {1, 1, 2, 2, ..., n, n} with no fixed points.at n=6A000459
• Penrice Christmas gift numbers, Card-matching numbers (Dinner-Diner matching numbers): Triangle T(n,k) = number of ways to get k matches for a deck with n cards, 2 of each kind.at n=36A059056
• Duplicate of A000459.at n=6A059072
• Square array read by antidiagonals: T(n,k) is the number of derangements of a multiset comprising n repeats of a k-element set.at n=38A372307