Investigating minimal repunits that divide by n.
Determining the first forty prime factors of a very large repunit.
Investigating which primes will never divide a repunit containing 10**n digits.
Determining the number of solutions of the equation x2 − y2 − z2 = n.
Determining the value of infinite polynomial series for which the coefficients are Fibonacci numbers.
Investigating isosceles triangle for which the height and base length differ by one.