Questions
What is the definition of Eulerian numbers?
- The number of permutations of n elements that have exactly k inversions.
- The number of permutations of n elements that have no inversions.
- The number of permutations of n elements that have exactly k fixed points.
- The number of permutations of n elements that have no fixed points.
What is the recurrence relation for Eulerian numbers?
- $A(n, k) = A(n-1, k-1) + (n-k)A(n-1, k)$
- $A(n, k) = A(n-1, k) + (n-k+1)A(n-1, k-1)$
- $A(n, k) = A(n-1, k) + (n-k)A(n-1, k+1)$
- $A(n, k) = A(n-1, k) + (n-k+1)A(n-1, k+1)$
What is the initial condition for Eulerian numbers?
- $A(0, 0) = 1$
- $A(1, 0) = 1$
- $A(0, 1) = 1$
- $A(1, 1) = 1$
What is the generating function for Eulerian numbers?
- $F(x) = \frac{1-x}{1-xe^x}$
- $F(x) = \frac{1+x}{1+xe^x}$
- $F(x) = \frac{1-x}{1+xe^x}$
- $F(x) = \frac{1+x}{1-xe^x}$
What is the asymptotic formula for Eulerian numbers?
- $A(n, k) \sim \frac{1}{k!}n^k$
- $A(n, k) \sim \frac{1}{k!}n^{k+1}$
- $A(n, k) \sim \frac{1}{k!}n^{k-1}$
- $A(n, k) \sim \frac{1}{k!}n^{k+2}$
What is the relationship between Eulerian numbers and Stirling numbers of the second kind?
- $A(n, k) = \sum_{i=0}^k S(n, i)$
- $A(n, k) = \sum_{i=0}^k S(n+1, i)$
- $A(n, k) = \sum_{i=0}^k S(n, i+1)$
- $A(n, k) = \sum_{i=0}^k S(n+1, i+1)$
What is the relationship between Eulerian numbers and Lah numbers?
- $A(n, k) = L(n, k+1)$
- $A(n, k) = L(n+1, k)$
- $A(n, k) = L(n, k)$
- $A(n, k) = L(n+1, k+1)$
What is the relationship between Eulerian numbers and Catalan numbers?
- $A(2n, n) = C_n$
- $A(2n+1, n) = C_n$
- $A(2n, n+1) = C_n$
- $A(2n+1, n+1) = C_n$
What is the relationship between Eulerian numbers and Motzkin numbers?
- $A(2n, n) = M_{2n}$
- $A(2n+1, n) = M_{2n+1}$
- $A(2n, n+1) = M_{2n}$
- $A(2n+1, n+1) = M_{2n+1}$
What is the relationship between Eulerian numbers and Narayana numbers?
- $A(n, k) = N(n, k+1)$
- $A(n, k) = N(n+1, k)$
- $A(n, k) = N(n, k)$
- $A(n, k) = N(n+1, k+1)$
What is the relationship between Eulerian numbers and Delannoy numbers?
- $A(n, k) = D(n, k+1)$
- $A(n, k) = D(n+1, k)$
- $A(n, k) = D(n, k)$
- $A(n, k) = D(n+1, k+1)$
What is the relationship between Eulerian numbers and Schröder numbers?
- $A(n, k) = S(n, k+1)$
- $A(n, k) = S(n+1, k)$
- $A(n, k) = S(n, k)$
- $A(n, k) = S(n+1, k+1)$
What is the relationship between Eulerian numbers and Genocchi numbers?
- $A(n, k) = G(n, k+1)$
- $A(n, k) = G(n+1, k)$
- $A(n, k) = G(n, k)$
- $A(n, k) = G(n+1, k+1)$
What is the relationship between Eulerian numbers and Bell numbers?
- $A(n, k) = B(n, k+1)$
- $A(n, k) = B(n+1, k)$
- $A(n, k) = B(n, k)$
- $A(n, k) = B(n+1, k+1)$
What is the relationship between Eulerian numbers and Fibonacci numbers?
- $A(n, k) = F(n+k)$
- $A(n, k) = F(n-k)$
- $A(n, k) = F(n+k+1)$
- $A(n, k) = F(n-k+1)$