That list is missing 9 and 18. Composite numbers have more than two factors. That list, when completed, comprises the first counting numbers with more than two factors.
The first six composite numbers are: 4, 6, 8 , 9, 10, and 12.
The numbers 4, 6, 8, 9, 10, 12, 14, 15, 16, 18 are the first ten composite numbers.
You can select 12 numbers for the first digit, 11 numbers for the second digit, and 10 numbers for the third digit; so 12*11*10 = 1320 sets of 3 numbers can be made out of 12 different numbers.
The first 10 composites are: 4, 6, 8, 9, 10, 12, 14, 15, 16, 18.
The first 12 composite numbers are 4, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, and 21.
The first 6 composite numbers are 4, 6, 8, 9, 10, and 12.
No, the first abundant number is 12.
12
2, 4, 6, 8, 10, 12, 14, 16, 18 and 20.
4, 6, 8, 9, 10, 12, 14, 15, 16, 18
4, 6, 8, 9, 10, 12, 14, 15, 16, 18
First 11 composite numbers are 4, 6, 8, 9, 10, 12, 14, 15, 16,18 and 20.