The pattern in the sequence 0, 3, 9, 21 involves adding consecutive odd numbers. Starting with 0, then adding 1+2, 3+6, and 9+12 gives you the next number in the sequence. Therefore, the next number would be 21 + 15 = 36.
It is 21 + 34 = 55
The answer is 21.Your numerical series is the beginning of a mathematical sequence called Fibonacci Numbers.The first number of the sequence is 0, the second number is 1, and each subsequent number is equal to the sum of the previous two numbers of the sequence itself (i.e. 0, 1, 1, 2, 3, 5, 8, 13, 21, etc.).
7203
The next number is 4, followed by -2
2+3=53+5=85+8=1313+21=3333 is the next number in this pattern. This pattern is called a Fibonacci.
28
It is 21 + 34 = 55
The next number in the sequence 3-15-6-30-21 is -207.
39. The rule here is starting with the number 9, add (-6 + sequence number * 6). 9 + (-6) = 3 3 + 0 = 3 3 + 6 = 9 9 + 12 = 21 21 + 18 = 39 39 + 24 = 63
the next number is 21 because it is adding the last number stated.
63
The next number is -21
21: (3)+3=(6)+4=(10)+5=(15)+6=(21)
The answer is 21.Your numerical series is the beginning of a mathematical sequence called Fibonacci Numbers.The first number of the sequence is 0, the second number is 1, and each subsequent number is equal to the sum of the previous two numbers of the sequence itself (i.e. 0, 1, 1, 2, 3, 5, 8, 13, 21, etc.).
If you mean: 1 1 2 3 5 8 13 21 then the next number is 13+21 = 34
7203
Looks Fibonacci, but you are missing the first 0... 0, 1, 1, 2, 3, 5, 8, 13, 21, 34, etc. where each number is the sum of the preceeding two.