  The very simple product of the number of particles by the number of holes
appearing in the expression of the reduced B(E2:0+->2+) transition probability
of even-even nuclei obtained from the extension of the seniority scheme is used
to analyze the experimental B(E2:0+->2+) values in the Cr up to Se isotopes. A
new interpretation is given to the B(E2:0+->2+) measured in 68Ni and 70Zn. The
B(E2:0+->2+) features of the even-even nuclei between Ni and Se with neutron
number ranging from 28 up to 50 fit in with a global scenario involving p-n
interaction. The evolution of the B(E2:0+->2+) curves presenting very large
values is amazingly reproduced by very schematic binomial calculations.
