Identifying what row a certain number first appears

[rwmill9716]

The table shows a series of numbers that are built from two rules (even number: n/2 for next number, odd number:3n+1 for next number - called Collatz Conjecture). When I put 22 in cell C4, there are 15 numbers developed following these two rules that end with a 1 in row 19. From that point on, the column cycles through the 1-4-2-1 sequence. I need a function in cell D4 that identifies the first time a 1 is reached in column C and identifies its associated number in column B.

 

[lrobbo314]

Is this what you're looking for?

Book1.xlsx
	B	C	D
4	Start Number	22	15
5	1	11
6	2	34
7	3	17
8	4	52
9	5	26
10	6	13
11	7	40
12	8	20
13	9	10
14	10	5
15	11	16
16	12	8
17	13	4
18	14	2
19	15	1
20	16	4
21	17	2
22	18	1
23	19	4
24	20	2
25	21	1
Sheet4

Cell Formulas
Range	Formula
D4	D4	=MATCH(1,C5:C167,0)
B5:B25	B5	=ROW()-4
C5:C25	C5	=IF(ISODD(C4),C4*3+1,C4/2)

 

[rwmill9716]

Thanks, IROBBO314, this works well.