Well, darling, it looks like we're playing a little game of "add some, skip a few" here. If you're following the pattern, the next number should be 41. But hey, if you wanna throw a curveball and say it's 42 just for fun, I won't judge.
21
The next number in the sequence 3-15-6-30-21 is -207.
The answer is 34. The full sequence is called the Fibonachi series. Your sequence is 3 5 8 13 21 3 + 5= 8 8 + 13 = 21 Therefore: 13 + 21 = 34
71422315
16 21 22 29
21
35
The next number in the sequence 3-15-6-30-21 is -207.
These are Fibannoci's numbers. Therefore, the 7th number is 21.
a
The next number in this sequence is 13112221.
The answer is 34. The full sequence is called the Fibonachi series. Your sequence is 3 5 8 13 21 3 + 5= 8 8 + 13 = 21 Therefore: 13 + 21 = 34
20
7203
It is: 34
71422315
16 21 22 29