Cyclotomic primes (degree>=5)

[Batalov]

Originally Posted by Batalov

P.S. Another one is Phi₇(p) (i.e. p⁶+p⁵+p⁴+p³+p²+p+1), where p=5978493*2^150006-1. With 270979 decimal digits, it is a bit short of entering the UTM prime database.

I decided to give another try to the search of Phi₇(x) primes.

I modified NewPGen to simultaneously sieve for p=kbⁿ-1 and Phi₇(p) and Phi₇(-p-1) (fixed n, sieve for k).
After sieving to 16T, llr/pfgw becomes faster for testing p values of which one would like to find 10-15 thousand...