Which of the following methods can be used to construct a pattern of 10 numbers for which it would be mathematically impossible to predict the 11th term?

(more then one answer.)

A.Make a pattern, starting with 3, where each number is the next digit of pi (3.14159 . . .).

B.Make a pattern by asking each of 10 friends what their favorite number is.

C.Make a pattern by counting the number of letters in each word of Lincoln's Gettysburg Address, starting with the first word.

D.Make a pattern based upon values assigned to the current weather.

E.Make a pattern where each number is the square of the number before it, plus 7 times the cube of the number before that.

2 answers

I'd say B and D, subject to a few assumptions
4. What is the value of the 11th term in the sequence?
-1 , 5 , 11 , 17 , 23 , ...