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: 1,472

9/bold-11.

Hey.

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**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 102,793

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.****If it ain't broke, fix it until it is.** **A number by itself is useful, but it is far more useful to know how accurate or certain that number is.**

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**mathgogocart****Member**- Registered: 2012-04-29
- Posts: 1,472

Omg.

Hey.

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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
- Posts: 3,246

13 - The unlucky number

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

Mathaholic | 10th most active poster | Maker of the 350,000th post | Person | rrr's classmate

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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'

I'm not crazy, my mother had me tested.

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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
- Posts: 3,246

7 - the luckiest number

That's why there's Lucky seven.

Mathaholic | 10th most active poster | Maker of the 350,000th post | Person | rrr's classmate

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**mathaholic****Member**- From: Earth
- Registered: 2012-11-29
- Posts: 3,246

2^57,885,161-1

Mathaholic | 10th most active poster | Maker of the 350,000th post | Person | rrr's classmate

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