Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

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**noelevans****Member**- Registered: 2012-07-20
- Posts: 236

1234567891 and 123456791 easy to remember primes for testing some things in number theory.

Also 31, 331, 3331, 33331, 333331, 3333331, 33333331 are all prime.

Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).

LaTex is like painting on many strips of paper and then stacking them to see what picture they make.

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**mathgogocart****Member**- Registered: 2012-04-29
- Posts: 1,431

9/bold-11.

Hey.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 90,482

The fourth repunit prime is huge

And no one knows how many of them there are!

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

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**mathgogocart****Member**- Registered: 2012-04-29
- Posts: 1,431

Omg.

Hey.

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
- Posts: 2,891
- Website

13 - The unlucky number

That's why there is a Friday the 13th!

"What is the square root of 2? 1.4141592653589793238" Seriously, I thought it was that. Too round?

3.141592653589793238...

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3691 the only primenumber I have noticed till now in a car's number plate

'And fun? If maths is fun, then getting a tooth extraction is fun. A viral infection is fun. Rabies shots are fun.'

'God exists because Mathematics is consistent, and the devil exists because we cannot prove it'

'You have made another human being happy. There is no greater accomplishment.' -bobbym

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
- Posts: 2,891
- Website

7 - the luckiest number

That's why there's Lucky seven.

"What is the square root of 2? 1.4141592653589793238" Seriously, I thought it was that. Too round?

3.141592653589793238...

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**mathaholic****Member**- From: Juliania
- Registered: 2012-11-29
- Posts: 2,891
- Website

2^57,885,161-1

"What is the square root of 2? 1.4141592653589793238" Seriously, I thought it was that. Too round?

3.141592653589793238...

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