freeCodeCamp/curriculum/challenges/en/08-coding-interview-prep/project-euler/problem-351-hexagonal-orchards.en.md

id, challengeType, title

id	challengeType	title
5900f4cb1000cf542c50ffde	5	Problem 351: Hexagonal orchards

Description

A hexagonal orchard of order n is a triangular lattice made up of points within a regular hexagon with side n. The following is an example of a hexagonal orchard of order 5:

Highlighted in green are the points which are hidden from the center by a point closer to it. It can be seen that for a hexagonal orchard of order 5, 30 points are hidden from the center.

Let H(n) be the number of points hidden from the center in a hexagonal orchard of order n.

H(5) = 30. H(10) = 138. H(1 000) = 1177848.

Find H(100 000 000).

Instructions

Tests

- text: <code>euler351()</code> should return 11762187201804552.
  testString: 'assert.strictEqual(euler351(), 11762187201804552, ''<code>euler351()</code> should return 11762187201804552.'');'

Challenge Seed

function euler351() {
  // Good luck!
  return true;
}

euler351();

Solution

// solution required