Tagged Questions
5
votes
4answers
514 views
How to find the sum all even numbers of this sequence?
I have a sequence $(u_{n})$
$$u_1= 1, \quad u_2 = 2, \quad u_3 = 3, \quad u_{n}= -u_{n-3} + 3u _{n-2} +2 u_{n-1}, \quad \forall n \geqslant 4.$$
I want to list the first $20$ terms of this sequence ...
12
votes
2answers
452 views
Suppressing negative roots in Mathematica
Problem
Using Mathematica's Solve operator can sometimes lead to an output involving a positive and negative root (say when solving for a variable such as ...
