Basic Problemscountinglinear
Lucas Numbers
Return the nth Lucas number, a sibling sequence to Fibonacci that starts 2, 1 and again sums the two previous terms. The first few terms run 2, 1, 3, 4, 7, 11.
Do this lesson first: climbing stairsThe full breakdown and animated table for this problem are still being written. In the meantime, run the four questions on it yourself — that is the whole exercise.