Project Euler Problem 049

# Statement

The arithmetic sequence, 1487, 4817, 8147, in which each of the terms increases by 3330,
is unusual in two ways: (i) each of the three terms are prime, and, (ii) each of the 4-digit
numbers are permutations of one another.

There are no arithmetic sequences made up of three 1-, 2-, or 3-digit primes, exhibiting this
property, but there is one other 4-digit increasing sequence.

What 12-digit number do you form by concatenating the three terms in this sequence?

# Solution

It's a brute-force approach with some performance improvements.

```from CommonFunctions import find_primes_less_than
from itertools import dropwhile

is_anagram = lambda x, y: sorted(str(x)) == sorted(str(y))

if __name__ == '__main__':
primes = find_primes_less_than(10000)
primes_greater_1000 = dropwhile(lambda x: x <= 1000, primes)
primes = set(primes)
found_one = False
for base in primes_greater_1000:
for increment in range(1, ((10000 - base) // 2)):
n1 = base + increment
n2 = base + increment * 2
if n1 in primes and n2 in primes and is_anagram(base, n1) and is_anagram(base, n2):
if found_one:
print("The result is:", str(base) + str(n1) + str(n2))
exit(0)
found_one = True
```