There is a column of numbers as follows: 4, 5, 9, 14, 23. What is the number 1999?

There is a column of numbers as follows: 4, 5, 9, 14, 23. What is the number 1999?

If f (n) is the nth term (n ∈ n +), then this sentence can be written as follows: F (1) = 4, f (2) = 5, f (n) = f (n-1) + F (n-2) (n ≥ 3). Obviously, this is a linear recursive sequence

2. In a column number 2,7,14,23 The tenth number in is

2+5=7
7+7=14
14+9=23
23+11+13+15+17+19+21=15*7=105

There is a column of numbers as follows: 4, 5, 9, 14, 23... Q, what is the remainder of the number in this column divided by three

The remainder of this sequence divided by 3 is
1,2,0,2,2,1,0,1,1,2,0,2,2,.
So the remainder is cycled every eight
2010 △ 8 = 251 + 2
So the remainder of the number 2010 divided by three is the same as the remainder of the number 2 divided by three, which is 2