What is the theorem / conjecture that the cube of any natural number a is equal to the sum of a continuous odd numbers? I want to know its name Has any textbook mentioned this theorem If yes, please tell me the publishing house, grade and page number

What is the theorem / conjecture that the cube of any natural number a is equal to the sum of a continuous odd numbers? I want to know its name Has any textbook mentioned this theorem If yes, please tell me the publishing house, grade and page number

Niches theorem