--- id: 5900f3ff1000cf542c50ff12 title: 'Problem 147: Rectangles in cross-hatched grids' challengeType: 5 forumTopicId: 301776 dashedName: problem-147-rectangles-in-cross-hatched-grids --- # --description-- In a 3x2 cross-hatched grid, a total of 37 different rectangles could be situated within that grid as indicated in the sketch. There are 5 grids smaller than 3x2, vertical and horizontal dimensions being important, i.e. 1x1, 2x1, 3x1, 1x2 and 2x2. If each of them is cross-hatched, the following number of different rectangles could be situated within those smaller grids: 1x1: 1 2x1: 4 3x1: 8 1x2: 4 2x2: 18 Adding those to the 37 of the 3x2 grid, a total of 72 different rectangles could be situated within 3x2 and smaller grids. How many different rectangles could be situated within 47x43 and smaller grids? # --hints-- `euler147()` should return 846910284. ```js assert.strictEqual(euler147(), 846910284); ``` # --seed-- ## --seed-contents-- ```js function euler147() { return true; } euler147(); ``` # --solutions-- ```js // solution required ```