More info on Conjuncture of Terros (Terras) In answering a coding problem called "Conjuncture of Terros", there was scant information on the series. **What is the origin of this series?** and what might applications may use it? See original problem Terros number sequence t(0) = n t(1) = n if t(n-1) is even t(n) = t(n-1)/2 else t(n) = (3*t(n-1) + 1)/2 Web search of "Terros" only led to some ADHD related sites. [Edit] @Palec provides a corrected spelling for Riho Terras

I would recommend searching for the Collatz Conjecture (also called 3n+1 problem). It's a more common name. A little explanation though:

You start with natural number $n$. If it's even, you go to $\frac{n}{2}$. If it is odd, you go to $3n+1$, which then will be even of course. Then repeat this process again and again. The Terros sequence is pretty much a modified Collatz sequence, just that you skip the even number $3n+1$ and directy go to $\frac{3n+1}{2}$. The interesting aspect is to find out where this sequence goes in the end. The conjecture states that for any starting point you end up in the circle $1\rightarrow4\rightarrow2\rightarrow1$. However this is not yet proven.

PS: For Terros the circle would of course be $1\rightarrow2\rightarrow1$.