Find the missing number.==> 3, 7, 23, x, 343, 1367

We have the terms of the sequence given as 3, 7, 23, x,
343, 1367. This does not have a common ratio or a common
difference.

Let's see what the difference between the terms
is

7-3 = 4

23 - 7 =
16

1367 - 343 = 1024

If we see
the difference 4 = 2^2 , 16 = 2^4, 1024 = 2^10

The
difference between the nth term and the (n + 1)th term can be expressed as
2^2n

Applying the same rule x - 23 should be 2^6
or

x - 23 = 64

=> x =
87

To verify we see that 343 - 87 = 256 which is
2^8.

The term to be found is x =
87.