Meeting on Beauty in Physics - Theory and Experiment in Honor of Francesco Lachello on the Occasion of his 70th Birthday, Mexico, 14 - 18 May 2012, vol.1488, pp.156-161, (Full Text)
The importance of the number of valence nucleons and its effect in nuclear binding to collective effects is discussed. In addition, a Si anomaly, an inconsistency between E(2(1)(+)) and S-2n, at N=20 is presented.