Formula to calculate squares in n x n grid?

Answer 1

# of possible square shapes viewed in a n x n grid

# of squares = (n)2 + (n-1)2 + (n-2)2 ... (1)2

Examples:

When n=1: 12 = 1

When n=2: 22 + 12 = 5

When n=3: 32 + 22 + 12 = 9 + 4 + 1 = 14

When n=4: 42 + 32 + 22 +12 = 16 + 9 + 4 + 1 = 30