Nicely done!
Quote:
Originally Posted by bsquared
At the risk of increasing confusion, I ran this through yafu's poly select and it slightly prefers the other degree 5:

Yes:
Quote:
Originally Posted by charybdis
You could also represent this number as 8*1281979*2^520+1, giving c5 = 10255832, c0 = 1, Y1 = 1, Y0 = 2^104. This choice of polynomial might even be slightly faster than yours; at least it has a higher Escore. For some numbers there will be even more polynomials to choose between: this will often be the case when near the crossover between degree 5 and degree 6, for instance (and here we have to testsieve, as Escores from different degrees are not comparable).

I suggested sieving on the rational side but YAFU just about prefers algebraic side for this polynomial  for a larger number this would call for testsieving. k*2^n+1 would be a rational side job for the usual small values of k (e.g. 1) but as k gets bigger so do the algebraic norms.