cannonball problem
词源说明
It can be visualized as the problem of taking a square arrangement of cannonballs on the ground and building a square pyramid out of them.
释义
专有名词proper noun
- 1(mathematics) The challenge of proving that the only solution of the Diophantine equation :∑n=1Nn2=M2 with N > 1 is when N = 24 and M = 70.