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Old 2016-03-16, 04:36   #7
LaurV
Romulan Interpreter
 
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Jun 2011
Thailand

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Let's totally confuse the poor guy...

Single line pari/gp to write 20 primes, based on idea that there are n/log(n) primes there, so finding a random one won't take more than few milliseconds (one in 28*log(10)~=64 random trials will be prime).

Code:
gp > cnt=0; while(cnt<20,w=vecextract(v=eval(Vec("9293392505711486960894715862")),numtoperm(#v,random((#v)!)));if(isprime(s=sum(x=1,#w,w[x]*10^(#w-x))),print(s);cnt++))
9182515166396028053899494277
5790252548878614912396160939
8065193970459846172863122599
821379790684859221594159663
2498239697461105998682175053
2875349516987619625293009841
9346719526110843569258970289
4214029397039916216865887559
9635892650907162274541988139
7341063961072859499825562819
513549761509632862849982179
7589344367589019966852211029
3114429320666258958905178997
5690190229723199638884574561
4808306291559199227865743169
4052135849669315891722986709
5875249935961716094202881693
7165899439027916658280945213
4402971315966388620295959187
9340551886459861239129076729
time = 181 ms.
gp >
The shorter ones have starting zeroes. Well... I could do one more test...
But you like my string-to-vector-to-random-permutation-to-number functions huh?

edit: how can I replace the sum? I would like a vector-to-string function, or a concat combination, which would not do any calculus, for even more obfuscation, but I don't know such pari function

Last fiddled with by LaurV on 2016-03-16 at 04:46
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