## Efficiency in Roman expression

Walkthrough of Project Euler problem #89

## Pandigitals with prime-divisible substrings

Walkthrough of Project Euler problem #43

## Multiple permutations

Walkthrough of Project Euler problem #32

## Circular primes

Walkthrough of Project Euler problem #35

## Fractions of a decimal fraction

Walkthrough of Project Euler problem #40

## Yet another naive BigInteger solution

Walkthrough of Project Euler problem #29

## Factorials of digits

Walkthrough of Project Euler problem #34

## Powers of digits

Walkthrough of Project Euler problem #30

## Bases and palindromes

Walkthrough of Project Euler problem #36

## Spiral square diagonals

Walkthrough of Project Euler problem #28

## The last digits of large numbers

Walkthrough of Project Euler problem #48

## Repeating decimals

Walkthrough of Project Euler problem #26