[0, 2, 4, 6, 8]
[1, 4, 9, 16, 25]
[0, 2, 4, 6, 8]
["quick", "brown", "jumps"]
[3, 5, 5, 3, 5]
[0, 10, 20, 30]
{0: 0, 1: 1, 2: 4, 3: 9, 4: 16}
{1: "a", 2: "bb", 3: "ccc"}
[[], [0], [0, 1], [0, 1, 2]]
sum of squares 1..7 = 140
