Subtract by 2 at a time.

(2)0, 1, 1,4,5,9, 14, 16,30,25(55)

Even positions: 1, 4, 9, 16, 25 are the squares of 1, 2, 3, 4, 5 in turn.

The second position: the sum of its previous number and its two numbers. So the third one is 1, 5, 14, 30, and finally 30+25.

(3) 1,2,5, 13,34(89 )

1+ 1=2

1+2+2=5

1+2+5+5= 13

1+2+5+ 13+ 13=34

1+2+5+ 13+34+34=89

(4) 1,3,4,7,7, 1 1( 18)

1) 100,84,76,72,70 (69)

Analysis: subtract 16 first, and then divide by two in turn. If 100- 16=84, then16 ÷ 2 = 8,84-8 = 76, then 8÷2=4 and 76-4.

(2)0, 1, 1,4,5,9, 14, 16,30,25(55

Analysis: When two adjacent numbers are added, we can think of 0+ 1= 1, 1+4=5, 5+9= 14,16 = 30, and take this as the basis.