Number of zero's in largest prime...

[paulunderwood]

The GMP program for 2^107-1 recorded a small negative time... but in fact took about 45 32-bit Athlon GHz-hours:

Exponent     Total number of zeroes
   2                   1
   3                   1
   5                   2
   7                   5
   13                  8
   17                  13
   19                  15
   31                  28
   61                  96
   89                  140
   107                 185

I am not going to attempt Lucas' 2^127-1

[R. Gerbicz]

Originally Posted by paulunderwood

The GMP program for 2^107-1 recorded a small negative time... but in fact took about 45 32-bit Athlon GHz-hours:

Oh, yes there is a problem in timing routine above about 1800 sec ( because I've used double variable ). But the program is good.

[jinydu]

Originally Posted by casevh

89 * ln(2) * [ln(ln(sqrt(2^89-1))) - ln(ln(3))]

I don't know what's going on. I evaluated that on Mathematica and I got 206, not 326...