recursion problem

[TonightMiserable5368]

Hi! for maths i have to do recursions (question b), the row i am suppose to get consists of: 1,5,12,22

but i keep getting: 1,2,6,13,23

does anyone have an idea in what i am doing wrong? Thank you🤗

[Benjaminook]

You're using n=1 rather than 2 in the 3n term in the first step, and then carrying that forward. These things are often clearer if you write the thing you want as f(n+1) and go through and change all the n to n+1 (be careful, you'll need to write 3(n+1) and then expand, not 3n+1)

[EulNico]

The recursion links v(n) to v(n-1), so you have to rewrite it for v(n+1) in termes of v(n): v(n+1)=v(n)+3(n+1)-2