perplexus.info :: Numbers : Thinking octal

Thinking octal (Posted on 2018-05-30)

In "A Mathematician's Apology", G. H. Hardy wrote:
"There are just four numbers, after unity, which are the sums
of the cubes of their digits: 153,370,371,407."

Clearly, he referred to base 10.

What are such numbers in base-8?
Provide your list in octal system.

See The Solution Submitted by Ady TZIDON

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Solution

| Comment 1 of 2

In "Solution", Jer wrote: "There are just five octal numbers, after unity, which are the sums of the cubes of their octal digits: 134, 205, 463, 660, 661."

Solved with a calculator program. It ran quickly enough that I searched up to 3000 octal just to be sure, since 4*7^3=2534octal.

Posted by Jer on 2018-05-30 09:22:09

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