133380

Appears in sequences

• Coefficient of x^5 in expansion of (1 + x + x^2)^n.at n=23A000574
• Triangle read by rows: T(n,k) is the number of hex trees with n edges and k pairs of adjacent vertices of outdegree 2.at n=18A126188
• Number of hex trees with n edges and no adjacent vertices of outdegree 2.at n=9A126189
• Coefficients of Laguerre recursive polynomials with an (n+2)!/2 multiplication factor and alpha=a0 =0 from Hochstadt: P(x, n) = (2*n + a0 + 1 - x)*P(x, n - 1)/(n + 1) - n*P(x, n - 2)/(n + 1);.at n=32A136533
• Number of n X 2 0..4 arrays with every 2 X 2 subblock containing exactly one value repeat, and new values 0..4 introduced in row major order.at n=5A209497
• Number of nX6 0..4 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..4 introduced in row major order.at n=1A209501
• T(n,k)=Number of nXk 0..4 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..4 introduced in row major order.at n=22A209503
• T(n,k)=Number of nXk 0..4 arrays with every 2X2 subblock containing exactly one value repeat, and new values 0..4 introduced in row major order.at n=26A209503
• Numbers k where A093653(k)/A000120(k) sets a new record.at n=30A360641
• a(n) = (n - 1) * (n - 2) * sigma(n).at n=39A374915
• G.f. A(x) satisfies: A(x) = A(x^2 + 2*x^3) / x.at n=18A389536