Продолжи ряд чисел 20, 18, 19, 17, 18, 16, 17..... 1,2, 4, 7, 11, 16, 22, 29
20,18,19,17,18,16,17,18,15,16,18,14,15,18 и т.д 1,2,4,7,11,16,22,29,37,46,56,67,79 и т.д.
20,18,19,17,18,16,17,15,1...... 17-2=15-14=1