A single number, such as 18233039, cannot define a series.
The pattern is add three and then multiply by three. The next number is 174.
The next two numbers are 26 & 78.
Dart Board
The difference between the numbers is increasing by 3 each time. Therefore, after a difference of 15 comes a difference of 18, therefore, the next number is 47 + 18 = 65.
162 and 486 the pattern is that the next number is three times the previous number.
162, 486, 1458
They are reducing by 4.5 each time. So the next two numbers are 9 and 4.5 after that.
The pattern is add three and then multiply by three. The next number is 174.
The next two numbers are 26 & 78.
18 and 6.
18, 22, 26 and 30 have two of the same factors as 16.
Based on the sample you have provided, I see that 4 numbers, counting by 2 from 12 to 18, form a repeating sequence. I would expect that the next 4 numbers in this series would again be 12, 14 16, and 18.
6 and 18
Dart Board
If you mean 288 144 72 36 then the next two numberes are 18 and 9 because they are being halved each time.
18
There are two pairs of prime numbers that express 18 as the sum of two prime numbers: 7 + 11 = 18 and 5 + 13 = 18.