In fact there is a "native" node "Progression" ! :D (arithmetic & Geometric)

And the "loop" is include inside the node...so only one volume is necessary at the start!
No need headaches for make loop structure! :) (for the moment)
Next step will be the random gap and from a given list!

http://moiscript.weebly.com/uploads/3/9/3/8/3938813/progression.nod





Curseur = Cursor, Bouge = Move, Sélectionné = Selected, Pas à Pas = Step by Step
Objets = Objects, Vers = Out, Facteur = Factor, Nombre = Number, Sortie = OutPut
Titre = Tittle

But normally your must be in English...