42318

Appears in sequences

• Number of n X 3 nonnegative integer arrays with upper left 0 and every value within 2 of its king move distance from the upper left and every value increasing by 0 or 1 with every step right, diagonally se or down.at n=34A252831
• Number of vertices in an equilateral triangle "frame" of size n (see Comments in A328526 for definition).at n=17A333031