[Jprogramming] New to J, problem 28

[Ralph G Selfridge]

This problem is the latest from Polivka in Quote-Quad (though aimed at 
APL). FWIW the answer is a cubic in the edge length.

Ralph Selfridge


On Sun, 2 Dec 2007, Roger Hui wrote:

> FYI: Problem 28 in www.ProjectEuler.net is as follows:
>
> Starting with the number 1 and moving to the right in a clockwise direction a 5 by 5 spiral is formed as follows:
>
> 21 22 23 24 25
> 20  7  8  9 10
> 19  6  1  2 11
> 18  5  4  3 12
> 17 16 15 14 13
>
> It can be verified that the sum of both diagonals is 101.
>
> What is the sum of both diagonals in a 1001 by 1001 spiral formed in the same way?
>
>