Prime Directive ?
By pgn
@pgntwo (22408)
Derry, Northern Ireland
May 17, 2017 3:06pm CST
Here's one for the mathematicians amongst us.
Most people know that a prime number is only divisible by itself or by 1, for example, the number "31".
So if you keep placing a 3 in front of 31, (331; 3,331; 33,331...), it stays prime until it reaches 333,333,331 (which factors into 19,607,843 x 17).
Why is that, I wonder...?
PS. I tested out some of the possibilities on WolframAlpha, a mathematical search engine, adding or removing a 3 each time:
To see full output on this page you need to enable JavaScript in your browser. Computing... Input: Result: Computing... Give us feedback » Computed by Wolfram Mathematica View Wolfram|Alpha in: Mobile | Standard © 2017 Wolfram Alpha LLC Terms of Use |
15 people like this
15 responses
@pgntwo (22408)
• Derry, Northern Ireland
18 May 17
Ah, a numerohobe, or an arithmophobe?
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3 people like this
@arthurchappell (45002)
• Preston, England
18 May 17
@pgntwo maths usually causes my mind to disintegrate
3 people like this
@Poppylicious (11133)
•
18 May 17
I'm afraid that I completely switched off when you mentioned the word mathematician. *makes the sign of the cross*
3 people like this
@DesirousDreamer (34780)
• Peoria, Arizona
17 May 17
I feel like someone has to be very bored to figure that out haha! But interesting nonetheless!
3 people like this
@much2say (53942)
• Los Angeles, California
17 May 17
My daughter has recently had to deal with good 'ol prime numbers and factoring in her math class . . . math makes her head hurt as much as it does mine (especially the way they teach it these days ). I wonder if her teacher knows about this one .
1 person likes this
@DaddyEvil (137142)
• United States
20 May 17
Hmmm... I am nowhere close to a mathematician, pgn... (I'm lucky I know what a prime number is, let alone most things involving math!)
Yes, I can add, subtract, multiply and divide in my head quite quickly, but you really should talk with @sishy7 about things like this! LOL!
1 person likes this
@DaddyEvil (137142)
• United States
21 May 17
@pgntwo Hmmm... not sure about that, pgn... maybe just the greedy people who hire them!
2 people like this
@pgntwo (22408)
• Derry, Northern Ireland
21 May 17
@DaddyEvil It could be - but the controllers must be hot with numbers too, I'd guess.
1 person likes this
@Mike197602 (15487)
• United Kingdom
17 May 17
I got a few A's in GCSE's and A levels...maths was not among the A's
PS...this discussion reminded me of Optimus Prime from the transformers...when pissed I look at his end speech from the film on youtube
1 person likes this
@Mike197602 (15487)
• United Kingdom
17 May 17
@pgntwo I like the linkin park track and I'm a fan of the megan fox/shia lebouf, or whatever his name is, films.
3 people like this
@pgntwo (22408)
• Derry, Northern Ireland
18 May 17
I had a play with this number series on the mathematical search engine, WolframAlpha, here's a sample - add or remove 3s until it starts to be "not prime":
To see full output on this page you need to enable JavaScript in your browser. Computing... Input: Result: Computing... Give us feedback » Computed by Wolfram Mathematica View Wolfram|Alpha in: Mobile | Standard © 2017 Wolfram Alpha LLC Terms of Use |
1 person likes this