3, -6, 12, 4, 20, 13, 27, 21, 33
-9, +18, -8, +16, -7, +14, -6, +12
25 is the next number that appears in that sequence.
The next number in the sequence is 20. You are alternately multiplying the previous number by two and then subtracting two.
16
8 The pattern is halve, add 4, halve, add 4,.. etc 8
The Next NumberThe next number is 25 if you use the following pattern: 5, (the number 10), 15 (the first number +10), (the number 10), and the next number is the third number +10 or 25.or you could think of it this way:5, 10 (+5), 15 (+5), -5 (10)The pattern is +5, +5, -5, so the next number would be 15, the next 20, and the next 15.
It is possible to find a polynomial of degree 5 such that any number at all can be made the next number in the sequence. However, using the following 4th degree polynomial, Un = (n4 - 15n3 + 85n2 - 225n + 274)/2 the next number is 20.
8
The pattern is plus 7. So the next number used to be 1.
The pattern appears to be: subtract 6, add 17, subtract 14, add 9, subtract 7. Following this pattern, the next number should be obtained by adding 3 to the last number in the sequence, which is 6. Therefore, the next number in the sequence is 9.
20
3, -6, 12, 4, 20, ?
37
The next number is 30.To see the pattern, write the numbers in two columns:12 1118 1424 17The left column increases by 6, the right column increases by 3. The next row is 30 and 20, so the missing number is 30.
42
10
10
4