Quote:
Originally Posted by MisterBitcoin
Not actually related to CRUS, but still interesting:
Primes for form 172*3^n+1
These are all primes n<25000.
Not going deeper, atm.

I still don't get it what is interesting about primes that can be found in less than half hour of pari/gp oneliner run? [/end of Sat_morning_grumpy_because_not_yet_coffee]
Code:
gp > for(n=1,50000,if(isprime(172*3^n+1),print("prime for: "n),printf("...%d...%c",n,13)))
prime for: 2
prime for: 4
prime for: 22
prime for: 25
prime for: 34
prime for: 44
prime for: 49
prime for: 54
prime for: 57
prime for: 114
prime for: 142
prime for: 265
prime for: 328
prime for: 360
prime for: 453
prime for: 520
prime for: 764
prime for: 1070
prime for: 2200
prime for: 3424
...3709...
*** at toplevel: for(n=1,50000,if(isprime(172*3^n+1),p
*** ^
*** isprime: user interrupt after 1min, 31,719 ms
*** Break loop: <Return> to continue; 'break' to go back to GP prompt
break>
(this is a slow laptop, which is factoring aliquotes in parallel, and yes, I understand that it gets slower and slower as it comes to higher n, without any sieving, but please come back with some 400k+ digits primes of this form, and then we talk...)
Going for that coffee... the machine is beeping...