Count how many n-digit positive integers exist which are also an nth power.
Find the continued fractions for N ≤ 10000 have an odd period.
Find the sum of digits in the numerator of the 100th convergent of the continued fraction for e.
Investigate the Diophantine equation x2 − Dy2 = 1.
Find the maximum total from top to bottom in a large triangle of numbers using an efficient algorithm.
Find the maximum 16-digit string for a “magic” 5-gon ring.
Find the value of n ≤ 1,000,000 for which n/φ(n) is a maximum.
Investigate values of n for which φ(n) is a permutation of n.
Listing reduced proper fractions in ascending order of size.
How many elements would be contained in the set of reduced proper fractions for d ≤ 1,000,000?