So, I do this at sixth form, but in further maths, so I guess it's closer to Uni maths than 'pre-college' work.

I'm really stuck, I can't even work out my base step for this proof properly!

Prove that the general term of the sequence described by

U(n+1) = 3U(n) + 4, n E Z+

is U(n) = 3^n - 2 n E Z+

where u(1) = 1

Normally, on the divisibility and series ones we've done, the base step is n=1, but I can't see how that's going to help me with this?!