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id	challengeType	title	forumTopicId
5900f4741000cf542c50ff86	5	Problem 263: An engineers' dream come true	301912

Description

Consider the number 6. The divisors of 6 are: 1,2,3 and 6. Every number from 1 up to and including 6 can be written as a sum of distinct divisors of 6: 1=1, 2=2, 3=1+2, 4=1+3, 5=2+3, 6=6. A number n is called a practical number if every number from 1 up to and including n can be expressed as a sum of distinct divisors of n.

A pair of consecutive prime numbers with a difference of six is called a sexy pair (since "sex" is the Latin word for "six"). The first sexy pair is (23, 29).

We may occasionally find a triple-pair, which means three consecutive sexy prime pairs, such that the second member of each pair is the first member of the next pair.

We shall call a number n such that : (n-9, n-3), (n-3,n+3), (n+3, n+9) form a triple-pair, and the numbers n-8, n-4, n, n+4 and n+8 are all practical,

an engineers’ paradise.

Find the sum of the first four engineers’ paradises.

Instructions

Tests

tests:
  - text: <code>euler263()</code> should return 2039506520.
    testString: assert.strictEqual(euler263(), 2039506520);

Challenge Seed

function euler263() {

  return true;
}

euler263();

Solution

// solution required

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