Thank you everyone!
It wasn't from a pattern - just put together the cubes as in the One Block Wonders Encore book by Maxine Rosenthal
http://books.google.fr/books?id=btQ0...onders&f=false
Very easy to do, no Y seams, you just construct it in strips then sew the strips together.
Pat - yes they are fun to make and then stand back and see the effect!