Example #1
0
def divisor_sigma_0(n):
    remain = n
    result = 1
    primes = util.primes_upto(int(n/2+1))
    i=0
    curr_mult = 0 # multiplicity of the current prime
    while i < len(primes):
        curr_prime = primes[i]
        if remain%curr_prime==0:
            remain = remain/curr_prime
            curr_mult += 1
        else:
            if curr_mult > 0:
                result *= curr_mult + 1
                curr_mult = 0
            i += 1
    return result==1 and n!=1 and 2 or result
Example #2
0
'''
Created on Mar 22, 2009

@author: mturner
'''
import util

t = util.Timer()
t.start()

# take a guess that n won't be larger than 200
# so...generate primes less than 200**2 + 1000*200 + 1000
n_max_guess = 200
val_max_guess = n_max_guess**2 + 1000*n_max_guess + 1000
primes = util.primes_upto(val_max_guess)
print "Found " + str(len(primes)) + " prime numbers."
primes_table = [False for x in range(val_max_guess)]
for i in primes:
    primes_table[i] = True
print "Finished constructing primes table"

max_pair = (0,0)
max_n = 0
for a in range(-999,1000):
    for b in range(-999,1000):
        n = 0
        while True:
            val = n**2 + a*n + b
            if val > val_max_guess:
                print "n_max_guess too small."
                break