41CL Quiz: Determinant of 30x30 anti-Identity matrix

[Valentin Albillo]

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Hi, Ángel:

(05-31-2018 07:40 AM)Ángel Martin Wrote:  BTW the benchmark with the 30x30 anti-identity matrix is now 16 seconds to calculate its determinant - down from the 11 minutes using the FOCAL program. And the result is -29.000000000 exact to 9 decimal places. Not bad! ;-)

You can do better ... ;-) ... Try this one out instead with your new machine-code functionality:

Consider the determinant D(N) = determinant of this NxN matrix:
 
      3    1    1 ... 1
      1    4    1 ... 1
      1    1    5 ... 1
      ... ... ... ... ...
      1    1    1 ... N+2

For example, D(3) = 50. Now compute and time D(11), D(13),D(30).

If you succeed in getting the correct integer values, see if you can find an exact formula for D(N)    (Hint: after a while, D(n) ends with more and more 0's).

Congratulations on your costly (in terms of your time and effort) achievement. Regards and have a nice weekend.
V.
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