February 1, 2013
On page 73 of his book Gödel, Escher, Bach: An Eternal Golden Braid, Douglas Hofstadter asks you to think about the following sequence:
1, 3, 7, 12, 18, 26, 35, 45, 56, 69, …
Hofstadter leaves you to figure out the rule that produces the sequence, though he does give some hints in the surrounding text.
Your task is to write a program that produces the first n elements of Hofstadter’s sequence. When you are finished, you are welcome to read or run a suggested solution, or to post your own solution or discuss the exercise in the comments below.