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PROJECT EULER · #0945

XOR-Equation C

Statement only · UnsolvedOriginal problem ↗
We use xy for the bitwise XOR of x and y.
Define the XOR-product of x and y, denoted by xy, similar to a long multiplication in base 2, except that the intermediate results are XORed instead of the usual integer addition.
For example, 73=9, or in base 2, 1112112=10012:
11111121111112111111211111291110012
We consider the equation:
(aa)(2ab)(bb)=cc

For example, (a,b,c)=(1,2,1) is a solution to this equation, and so is (1,8,13).

Let F(N) be the number of solutions to this equation satisfying 0abN. You are given F(10)=21.

Find F(107).

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