def f(n) @count = 0 seq = [n] (1..n).each do |k| seq[1] = k g(seq) end @count end def g(seq) max = (seq[-1] - seq[-2]).abs - 1 @count += 1 # p [seq[0], seq[2..]] p seq (1..max).each do |k| seq << k g(seq) seq.pop end end p f(5) def h(n) seq = [n, 0] @count = 0 g(seq) @count end # h(4)