# Could I have found an Easter egg in Brilliant's Calcdoku problems?

I used Snipping Tool for this so, yeah, not my best artistic work :)

See the black squares containing 4 numbers each. Each black square has the numbers 1,2,3 and 4 exactly once. Now look at the middle red square. Same property applies. Looks like the regional rule does apply here, unlike the rule given in the Calcdoku prefaces -

"...There is no region rule as in Sudoku..."

...which applies to the 4x4 grid also, mind you, as that has also been mentioned in all the prefaces.

I am wondering if I just uncovered an Easter egg in Brilliant's famous Calcdoku problems. This is because the example 4x4 grid in the prefaces also follows this property -

Yup, this one follows the property too

This is why I would like to explore the other Calcdoku problems and check if I just found a sneaky Easter egg from Brilliant. So if you're a Premium member, please help me out by taking pics of the solved Calcdoku's and sending them to me here.

Findings -

I have found that Calcdoku 9, which has 4 solution, obeys this rule for each of its solutions.

Sadly, not other Calcdoku's show this property. It was fun trying to find an Easter egg and solving all thosee Calcdoku problems though :)

Note by Percy Jackson
3 months, 2 weeks ago

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- 3 months, 2 weeks ago

@Abhinav Kumar - Go to a question which you got correct, and go to the place where you post solutions. There, you will see this at the top -

Click the boxed button of a picture, and select the pictures from your device files. There will be a code generated, which you can send to me in the previous note i mentioned.

- 3 months, 2 weeks ago

Calcdoku 1 Calcdoku 2 Calcdoku 3 Calcdoku 4 Calcdoku 5 Calcdoku 6 Calcdoku 7 Calcdoku 8 Calcdoku 9 Calcdoku 10 Calcdoku 11 Calcdoku 12 Calcdoku 13 Calcdoku 14

- 3 months, 2 weeks ago

@Percy Jackson I have sent them

- 3 months, 2 weeks ago

Thanks, but could you send their solutions, because I want to check whether they follow regional rule of Sudoku. Thanks :)

- 3 months, 2 weeks ago

Can't you solve them, please? I think solving fourteen in a day might be too many for me 😅

- 3 months, 2 weeks ago

Yes, I've solved them, but I don't have time to edit the pictures to show the solution images. Thanks anyway, I'll do it later I guess :)

- 3 months, 2 weeks ago

@Percy Jackson So was the region rule you found correct?

- 3 months, 2 weeks ago

No, I found it once more in the 9th Calcdoku, but the other's weren't showing the property.

- 3 months, 2 weeks ago

A really interesting, sneaky Easter egg! @Percy Jackson, I commend you!

- 3 months, 2 weeks ago

Thank you! Sadly, the only other Calcdoku to follow this property is the 9th one, so its not a really recurring Easter egg, but a fun one to find and solve though :)

- 3 months, 2 weeks ago