Problem 49 Prime permutations
Problem 49: Prime permutations
The arithmetic sequence, 1487, 4817, 8147, in which each of the terms increases b[……]
Problem 48 Self powers
Problem 48: Self powers
The series, 11 + 22 + 33 + … + 1010 = 10405071317.
Find the last ten digits of the ser[……]
Problem 47 Distinct primes factors
Problem 47: Distinct primes factors
The first two consecutive numbers to have two distinct prime factors are:
14[……]
Problem 46 Goldbach’s other conjecture
Problem 46: Goldbach’s other conjecture
It was proposed by Christian Goldbach that every odd composite number ca[……]
Problem 45 Triangular, pentagonal, and hexagonal
Problem 45: Triangular, pentagonal, and hexagonal
Triangle, pentagonal, and hexagonal numbers are generated by t[……]
Problem 43 Sub-string divisibility
Problem 43: Sub-string divisibility
The number, 1406357289, is a 0 to 9 pandigital number because it is made up[……]
Problem 42 Coded triangle numbers
Problem 42: Coded triangle numbers
The nth term of the sequence of triangle numbers is given by, tn = ½n(n+1); s[……]
Problem 41 Pandigital prime
Problem 41: Pandigital prime
We shall say that an n-digit number is pandigital if it makes use of all the digits[……]
Problem 40 Champernowne’s constant
Problem 40: Champernowne’s constant
An irrational decimal fraction is created by concatenating the positive inte[……]
Problem 39 Integer right triangles
Problem 39: Integer right triangles
If p is the perimeter of a right angle triangle with integral length sides,[……]
Problem 38 Pandigital multiples
Problem 38: Pandigital multiples
Take the number 192 and multiply it by each of 1, 2, and 3:
192 × 1 = 192
192 ×[……]
Problem 37 Truncatable primes
Problem 37: Truncatable primes
The number 3797 has an interesting property. Being prime itself, it is possible t[……]
Problem 36 Double-base palindromes
Problem 36: Double-base palindromes
https://projecteuler.net/problem=36
The decimal number, 585 = 10010010012 (binary), is palindromic in both bases.
[……]
Problem 35 Circular primes
Problem 35: Circular primes
The number, 197, is called a circular prime because all rotations of the digits: 197[……]
Problem 34 Digit factorials
Problem 34: Digit factorials
145 is a curious number, as 1! + 4! + 5! = 1 + 24 + 120 = 145.
Find the sum of all[……]