123216

Appears in sequences

• Numbers n such that sigma(n) = 4*(n-phi(n)).at n=12A068420
• Number of ways to choose four collinear points from an n X n grid.at n=16A178256
• Conjectured row or column n=4 of array A205497.at n=5A205494
• Convolution related to array A205497 and to generating functions for the rows of the array form of A050446.at n=4A205495
• Triangle read by rows: Zig-zag Eulerian number triangle T(n, k).at n=51A205497
• Triangle read by rows: Zig-zag Eulerian number triangle T(n, k).at n=52A205497
• Number of snake-like polyominoes with the maximum possible number of unit squares in an n X n square.at n=13A331986
• a(n) = A205497(n, floor((n - 1) / 2)). The middle coefficients of the Eulerian zig-zag polynomials.at n=11A373755