Is a closed form expression for this recurrence relation possible?

24 Views Asked by At

Consider the relation

$$t_{n}=t+t_{n-1}+\sqrt{(t+t_{n-1})^{2}+t^{2}}, n>1$$

with $t_{1}=(1+\sqrt{2})t$.

Is it possible to get a closed form expression for this relation?

I found that

$$t_{2}=\left(2+\sqrt{2}+\sqrt{7+4\sqrt{2}}\right)t$$

but after this it seems to get harder unless there is a pattern.