Quote:
Originally Posted by grandpascorpion

That's a tough problem.
If
is such that for some
of its divisors:
, we have
for
then
for
form a sequence of
squares whose second differences equal the constant
.
For example,
gives a sequence of squares
whose second differences equal
.
Finding sequences of squares with constant second differences is a rather hard task (see the attached paper) and additional requirement of having difference of the special form
makes it even harder.