Number Theory

[teebee]

I solved it using http://www.alpertron.com.ar/ECM.HTM and http://primes.utm.edu/lists/small/1000.txt. However, I wonder whether the factor 433^11 has been intentionally omitted. Nevertheless, a nice challenge.

[therethinker]

Thanks, and nice use of tools! It wasn't mean to be incredibly hard to factor; the challenge was deciphering the encoding scheme.

Also, 433^11 was not intentional, I'll let adum know

[CodeX]

Once again Mathematica has proven itself to be a wonderful tool:

Code: Select all

n = 364843790094573992692171828893958267226605666939892572894047098638\
9184961532284016919213346409983710756329032006862785922310236412226440\
1785848633686914239718396824942863542362872670850647423969609315959515\
511402019435615717737240510626468808851903266920099765545245394707;

FromCharacterCode[
	PrimePi[#1[[1]]] & /@ Sort[FactorInteger[n], #1[[2]] < #2[[2]] &]
]

Execution time of 15ms, poking around time: a bit longer

[laz0r]

I used mathematica too, and I must say I was in awe at the speed.

Working out the relation they had with other primes to form letters took slightly longer though. Great challenge!

[magnus]

Great challenge - The solution having each character exactly once made it even harder.

[Hippo]

Interesting ... first attempt lead naturally to the solution ...

[yes-man]

After initially leaving it for a few years, this challenge turned out to be a nice one.
First attempts involved reading it in binary .. *d'uh* .. Okay. Primes it was.
After that it was okay-ish. (With the hint from laz0r)