Today is a very special day. It’s the birthday of only one girlfriend of programmer Shojib. Now, you all know, he wants to give a special gift to her. He wants to give her a rich ornament. To make the ornament very special he decided to make it as a hexagons shapes where the number of pearls in the ornament will consist of the outlines of regular hexagons with sides up to N pearls, when the hexagons are overlaid so that they share one vertex. The figure of the ornament will quite be like in the following.
This is a companion discussion topic for the original entry at https://toph.co/p/find-the-number-of-pearls