“…(1.2) This sequence has many interesting properties (see [3,7,16,23] and references therein), in particular its 'Kepler limit', that is the limit of the ratio of consecutive terms (see [6,8]), is the so-called Plastic number. This number has a certain relevance in contemporary Architecture (see [12,16,17]), and it is considered the key to finding the right proportion among spatial figures at the same way that the Golden Mean is considered for the flat ones (see [15]).…”