--- id: 5900f4cb1000cf542c50ffde title: 'Problem 351: Hexagonal orchards' challengeType: 5 forumTopicId: 302011 dashedName: 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: hexagonal orchard of order 5, with highlighted in green points, which are hidden from the center by a point closer to it 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 $n$. $H(5) = 30$. $H(10) = 138$. $H(1\\,000)$ = $1\\,177\\,848$. Find $H(100\\,000\\,000)$. # --hints-- `hexagonalOrchards()` should return `11762187201804552`. ```js assert.strictEqual(hexagonalOrchards(), 11762187201804552); ``` # --seed-- ## --seed-contents-- ```js function hexagonalOrchards() { return true; } hexagonalOrchards(); ``` # --solutions-- ```js // solution required ```