Given ANY number is it easy to find a polynomial of order 5 that will fit the five given numbers and the selected sixth.
However, the simplest polynomial to fit the above numbers is
Un = (3n2 - 3n + 4)/2 for n = 1, 2, 3, ...
Accordingly, the next number is 47.
next in the sequence: 10,20,30,20
14
14
The next number in the sequence will be 56.
20
Think it's 30...then 20
10
25 is the next number that appears in that sequence.
A number sequence is not a question. So there can be no "answer".
500
11 and 8
10 is one possibility.