141520

Appears in sequences

• Number of 4 X n (0,1) matrices such that each row and each column is nondecreasing or nonincreasing.at n=19A086114
• a(n) = Sum_{1 <= i < j <= n} F(i)*F(j), where F(k) is the k-th Fibonacci number.at n=12A190173
• Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any horizontal, diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-3.at n=7A212022
• T(n,k)=Number of lower triangular n X n arrays colored with integers 0 upwards introduced in row major order, with no element equal to any horizontal, diagonal or antidiagonal neighbor, and containing the value n(n+1)/2-k-1.at n=43A212026
• Triangle of generalized Stirling numbers of the second kind S(n,k) associated with the generalized Bell numbers A271049(n); S(n,k) = Sum_{j=0..k} (-1)^(k-j)*binomial(k,j)*Gamma((j+2)/3)*Gamma(3*n+j-1)/(Gamma(j)*Gamma(n+(j-1)/3))/(3^(n-1)*k!).at n=16A271204
• The number of ways of seating n people around a table for the second time so that k pairs are maintained. T(n,k) read by rows.at n=60A326390