What is the next number in the sequence 1123581321?

Answer 1

The next number in this well-known Fibonacci Series of numbers is 34. It is usually written with a space and /or comma between the terms, and starts with one, i.e. 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89,...

The next number in the sequence is found by adding the previous 2 numbers together:

for any n where in is a natural number: F(n+1) = F(n) + F(n-1)

So:

1 + 1 = 2

1 + 2 = 3

2 + 3 = 5

-

-

-

13 + 21 = 34

etc...

Answer 2

The answer to your sequence is 41122314 and then 31221324. The next number in the sequence is in the form of a1b2c3d4e5..., where "a" is the quantity of 1 in the previous line, "b" is the quantity of 2 in the previous line, etc etc.

Another way I have seen this type of sequence is this:

1

11

21

1211

111221

312211

12112221

1112213211

The sequence is made by "reading" the line before it. The first line is One of the number One, so thus the second line is 1 1. The second line is Two Ones, so 2 1. The third line is One Two, One One, so 1211. In turn, this is One One, One Two, Two Ones, so 11 12 21.

Answer 3

T(1) = 1T(2): T(1) consists of 1 1 so 11

T(3): T(2) consists of 2 1s so 21

T(4): T(3) consists of 1 2 followed by 1 1 so 1211

T(5): T(4) consists of 1 1 followed by 1 2 followed by 2 1s so 111221

T(6): T(5) consists of 3 1s followed by 2 2s followed by 1 1 so 312211

and then

T(7): T(6) consists of 1 3 followed by 1 1 followed by 2 2s followed by 2 1s so 13112221

and so on.

Answer 4

Let's see, you end with 312221133112. That has one 3, one 1, three 2s, two 1s, two 3s, two 1s and one 2. Next in this sequence is: 13113221232112

Answer 5

1,234,321 123,454,321 12,345,654,321 1,234,567,654,321 123,456,787,654,321. You add 1 to the last number in the middle.

Answer 6

The next number in the series is 13112221.

Answer 7

312213 212223

Answer 8

31131211131221

Answer 9

1112311