1, and find the increment from n- 1 to n-th;

2. Find the total increase from 1 to the nth place;

3. The 1 bit of the sequence plus the total increment is the nth bit.

In general, it is relatively simple to ask the first and second questions about finding patterns. If you really can't find the rules, you should also write down your own thoughts. If you can get one point, you get one point.

There are many mathematical thinking methods in junior high school mathematics, the most basic and main ones are: reduction thinking method, combination of numbers and shapes thinking method, classified discussion thinking method, function and equation thinking method and so on.

Arithmetic progression: The difference between adjacent numbers is equal, and the whole series increases or decreases in turn. Arithmetic progression is one of the common ranking rules in digital reasoning test.

The general formula of arithmetic progression {an} is: an = a1+(n-1) D. The first n terms and formulas are: sn = n * a1+n (n-1) d/2 or sn = n (a Note: All the above n are positive integers.

Geometric series refers to a series in which the ratio of each term to its previous term is equal to the same constant from the second term, usually expressed by G and P. This constant is called the common ratio of geometric series, usually expressed by the letter Q (q≠0), and geometric series a 1≠ 0. Where each item in {an} is not 0. Note: When q= 1, an is a constant series.