DNA - 12 generation chart

1st generation = self
2nd generation = 2 parents
3rd generation = 4 grandparents
4th generation = 8 great-grandparents
5th generation = 16 great-great-grandparents
6th generation = 32 great-great-great-grandparents
7th generation = 64 great-great-great-great-grandparents
8th generation = 128 G5-grandparents
9th generation = 256 G6-grandparents
10th generation = 512 G7-grandparents
11th generation = 1,024 G8-grandparents
12th generation = 2,048 G9-grandparents
13th generation = 4,096 G10-grandparents
14th generation = 8,192 G11-grandparents
15th generation = 16,384 G12-grandparents
16th generation = 32,768 G13-grandparents
17th generation = 65,536 G14-grandparents
18th generation = 131,072 G15-grandparents
19th generation = 262,144 G16-grandparents
20th generation = 524,288 G17-grandparents
21st generation = 1,048,576 G18-grandparents
22nd generation = 2,097,152 G19-grandparents
23rd generation = 4,194,304 G20-grandparents
24th generation = 8,388,608 G21-grandparents
25th generation = 16,777,216 G22-grandparents
26th generation = 33,554,432 G23-grandparents
27th generation = 67,108,864 G24-grandparents
28th generation = 134,217,728 G25-grandparents
29th generation = 268,435,456 G26-grandparents
30th generation = 536,870,912 G27-grandparents
31st generation = 1,073,741,824 G28-grandparents
32nd generation = 2,147,483,648 ancestors (or G29-grandparents)

"So all the generations from Abraham to David are fourteen generations; from David to the deportation to Babylon, fourteen generations; and from the deportation to Babylon to the Messiah, fourteen generations." (Matthew 1:17)

14+14+14=42