A single number, such as 4642142824816 does not constitute a sequence.
I would make it 1 The above sequence is the numerical order of some of the numbers on a dart board
are you sure it is not1 2 3 6 8 7 14 16because that sequence doubles for the first one, then adds two for the next number, then subtracts one for the third, then repeats. So the next number is 15.
From the given sequence, the pattern appears to be 47-42=4, 42/3=14, 14*2=28, 28-4=24, 24/3=8, 8*2=16 and therefore the next number will be 16-4=12.
21
18
14
14
11
11
11.
14
17?
14 20.02.18.04.16.06.14.08.12.10.10.12.08.14.06.16.04.18.02.20
Think it's 30...then 20
14
10