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-   -   13x666=2020 (https://www.mersenneforum.org/showthread.php?t=26229)

henryzz 2020-11-26 12:08

[QUOTE=petrw1;564401]is SQRT(666*666) cheap?[/QUOTE]

Was trying to avoid that

swishzzz 2020-11-26 18:53

(666 + (666+666+666)/666) * (13+13+13)/13 + 13

Uses 5 of each.

swishzzz 2020-11-26 20:26

13 * (13*13+13-666/(13+13)) - 13

8 numbers used.

R. Gerbicz 2020-11-26 20:58

[QUOTE=petrw1;564343]
Find a formula using only 13 and 666 to get 2020.
You can only use +. -, x, /, ^, !, √

1. Find an answer with the fewest numbers (not digits).
2. Find an answer with the same number of each; and the fewest.

[/QUOTE]

For Q2 the optimal is 9 terms (using 4 pieces of 13 and 5 pieces 666):
[CODE]
13-(666-(666+666)*(666+13*(13+13)))/666
[/CODE]
and for Q1 the optimal is the above 8 terms.
Assuming that we would use "only" the +,-,*,/ operations (no other crazy . or concat) and no large (intermediate) numbers.

swishzzz 2020-11-26 21:29

I've proven by brute force search that there does not exist a solution using either 7 numbers or 4 of each, if we only allow the simple operators +, -, *, /.

The closest solution with 4 of each is 13 + 13 + 666 + 666 + 666 - 666/(13*13) = 2020.05917...

swishzzz 2020-11-26 21:44

2020 = 666 + 666 + 666 + sqrt(666 - 13*13 - 13)

7 numbers.

VBCurtis 2020-11-26 22:46

[QUOTE=swishzzz;564498]2020 = 666 + 666 + 666 + sqrt(666 - 13*13 - 13)

7 numbers.[/QUOTE]

Genius!

Viliam Furik 2020-11-27 12:21

[QUOTE=swishzzz;564498]2020 = 666 + 666 + 666 + sqrt(666 - 13*13 - 13)

7 numbers.[/QUOTE]

Nice!

henryzz 2020-11-27 14:00

[QUOTE=swishzzz;564498]2020 = 666 + 666 + 666 + sqrt(666 - 13*13 - 13)

7 numbers.[/QUOTE]

Very impressive

Note this can be converted to 4 of each quite easily:
2020 = 666 + 666 + 666 + sqrt(666 - 13*(13+13/13))

It would surprise me if these are beaten

Ensigm 2020-11-27 16:19

[QUOTE=swishzzz;564498]2020 = 666 + 666 + 666 + sqrt(666 - 13*13 - 13)

7 numbers.[/QUOTE]
[QUOTE=henryzz;564568]
Note this can be converted to 4 of each quite easily:
2020 = 666 + 666 + 666 + sqrt(666 - 13*(13+13/13))

It would surprise me if these are beaten[/QUOTE]
I can only marvel at these.

robert44444uk 2020-11-28 11:23

[QUOTE=henryzz;564568]Very impressive

Note this can be converted to 4 of each quite easily:
2020 = 666 + 666 + 666 + sqrt(666 - 13*(13+13/13))

It would surprise me if these are beaten[/QUOTE]

Got to love it.

The newspapers need to be told - the World needs to know :alien:

I suggest the Daily Mail or the Sun in the UK, and Fox News for the telly. And the boys and girls in QAnon, and the anti Vaxxers, and the Covid deniers, and, and....


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