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Problem 354


Problem 354


Distances in a bee’s honeycomb

Consider a honey bee’s honeycomb where each cell is a perfect regular hexagon with side length 1.

One particular cell is occupied by the queen bee.
For a positive real number L, let B(L) count the cells with distance L from the queen bee cell (all distances are measured from centre to centre); you may assume that the honeycomb is large enough to accommodate for any distance we wish to consider.
For example, B(√3) = 6, B(√21) = 12 and B(111 111 111) = 54.

Find the number of L ≤ 5·1011 such that B(L) = 450.


蜜蜂蜂巢距离

蜜蜂蜂巢的每个单元都是边长为1的正六边形。

其中一个单元被蜂后占据。
对于正实数L,记B(L)为距离蜂后所在单元的距离为L的单元总数(单元的距离指单元中心之间的距离);你可以假定蜂巢足够大,允许我们在本题中考虑任意远的距离。
例如,B(√3) = 6,B(√21) = 12以及B(111 111 111) = 54。

有些L ≤ 5·1011满足B(L) = 450,求所有这样的L的数目。