euler

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	<img src="../assets/euler.png">
	<h1>euler</h1>
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> My solutions to many of Project Euler's problems.

The source code can be found in the [src](src) directory. My thoughts about some puzzles may also be found in the [thoughts](thoughts) directory, showing my thought process or providing some mathematical insight. As per the rules of the challenge, I may only publish the solutions to the first 100 problems here, so I will stop after that but still continue the challenge.

### Checklist

-   [x] [1 - Multiples of 3 or 5](src/1%20-%20Multiples%20of%203%20or%205.ts)
-   [x] [2 - Even Fibonacci numbers](src/2%20-%20Even%20Fibonacci%20numbers.ts)
-   [x] [3 - Largest prime factor](src/3%20-%20Largest%20prime%20factor.ts)
-   [x] [4 - Largest palindrome product](src/4%20-%20Largest%20palindrome%20product.ts)
-   [x] [5 - Smallest multiple](src/5%20-%20Smallest%20multiple.ts)
-   [x] [6 - Sum square difference](src/6%20-%20Sum%20square%20difference.ts)
-   [x] [7 - 10001st prime](src/7%20-%2010001st%20prime.ts)
-   [x] [8 - Largest product in a series](src/8%20-%20Largest%20product%20in%20a%20series.ts)
-   [x] [9 - Special Pythagorean triplet](src/9%20-%20Special%20Pythagorean%20triplet.ts)
    -   [Thoughts](thoughts/9%20-%20Special%20Pythagorean%20triplet.md)
-   [x] [10 - Summation of primes](src/10%20-%20Summation%20of%20primes.ts)
    -   [Thoughts](thoughts/10%20-%20Summation%20of%20primes.md)
-   [x] [11 - Largest product in a grid](src/11%20-%20Largest%20product%20in%20a%20grid.ts)
-   [x] [12 - Highly divisible triangular number](src/12%20-%20Highly%20divisible%20triangular%20number.ts)
-   [x] [13 - Large sum](src/13%20-%20Large%20sum.ts)
-   [x] [14 - Longest Collatz sequence](src/14%20-%20Longest%20Collatz%20sequence.ts)
-   [x] [15 - Lattice paths](src/15%20-%20Lattice%20paths.ts)
    -   [Thoughts](thoughts/15%20-%20Lattice%20paths.md)
-   [x] [16 - Power digit sum](src/16%20-%20Power%20digit%20sum.ts)
-   [x] [17 - Number letter counts](src/17%20-%20Number%20letter%20counts.ts)
-   [x] [18 - Maximum path sum I](src/18%20-%20Maximum%20path%20sum%20I.ts)
-   [x] [19 - Counting Sundays](src/19%20-%20Counting%20Sundays.ts)
-   [x] [20 - Factorial digit sum](src/20%20-%20Factorial%20digit%20sum.ts)
-   [ ] 21 - Amicable numbers
-   [ ] 22 - Names scores
-   [ ] 23 - Non-abundant sums
-   [ ] 24 - Lexicographic permutations
-   [ ] 25 - 1000-digit Fibonacci number
-   [ ] 26 - Reciprocal cycles
-   [ ] 27 - Quadratic primes
-   [ ] 28 - Number spiral diagonals
-   [ ] 29 - Distinct powers
-   [ ] 30 - Digit fifth powers
-   [ ] 31 - Coin sums
-   [ ] 32 - Pandigital products
-   [ ] 33 - Digit cancelling fractions
-   [ ] 34 - Digit factorials
-   [ ] 35 - Circular primes
-   [ ] 36 - Double-base palindromes
-   [ ] 37 - Truncatable primes
-   [ ] 38 - Pandigital multiples
-   [ ] 39 - Integer right triangles
-   [ ] 40 - Champernowne's constant
-   [ ] 41 - Pandigital prime
-   [ ] 42 - Coded triangle numbers
-   [ ] 43 - Sub-string divisibility
-   [ ] 44 - Pentagon numbers
-   [ ] 45 - Triangular, pentagonal, and hexagonal
-   [ ] 46 - Goldbach's other conjecture
-   [ ] 47 - Distinct primes factors
-   [ ] 48 - Self powers
-   [ ] 49 - Prime permutations
-   [ ] 50 - Consecutive prime sum
-   [ ] 51 - Prime digit replacements
-   [ ] 52 - Permuted multiples
-   [ ] 53 - Combinatoric selections
-   [ ] 54 - Poker hands
-   [ ] 55 - Lychrel numbers
-   [ ] 56 - Powerful digit sum
-   [ ] 57 - Square root convergents
-   [ ] 58 - Spiral primes
-   [ ] 59 - XOR decryption
-   [ ] 60 - Prime pair sets
-   [ ] 61 - Cyclical figurate numbers
-   [ ] 62 - Cubic permutations
-   [ ] 63 - Powerful digit counts
-   [ ] 64 - Odd period square roots
-   [ ] 65 - Convergents of e
-   [ ] 66 - Diophantine equation
-   [x] [67 - Maximum path sum II](src/67%20-%20Maximum%20path%20sum%20II.ts)
-   [ ] 68 - Magic 5-gon ring
-   [ ] 69 - Totient maximum
-   [ ] 70 - Totient permutation
-   [ ] 71 - Ordered fractions
-   [ ] 72 - Counting fractions
-   [ ] 73 - Counting fractions in a range
-   [ ] 74 - Digit factorial chains
-   [ ] 75 - Singular integer right triangles
-   [ ] 76 - Counting summations
-   [ ] 77 - Prime summations
-   [ ] 78 - Coin partitions
-   [ ] 79 - Passcode derivation
-   [ ] 80 - Square root digital expansion
-   [ ] 81 - Path sum: two ways
-   [ ] 82 - Path sum: three ways
-   [ ] 83 - Path sum: four ways
-   [ ] 84 - Monopoly odds
-   [ ] 85 - Counting rectangles
-   [ ] 86 - Cuboid route
-   [ ] 87 - Prime power triples
-   [ ] 88 - Product-sum numbers
-   [ ] 89 - Roman numerals
-   [ ] 90 - Cube digit pairs
-   [ ] 91 - Right triangles with integer coordinates
-   [ ] 92 - Square digit chains
-   [ ] 93 - Arithmetic expressions
-   [ ] 94 - Almost equilateral triangles
-   [ ] 95 - Amicable chains
-   [ ] 96 - Su Doku
-   [ ] 97 - Large non-Mersenne prime
-   [ ] 98 - Anagramic squares
-   [ ] 99 - Largest exponential
-   [ ] 100 - Arranged probability