def problem187(): GOAL = 10**8 m = rwh_primes2(GOAL) primes = orderedlist(m) count = 0 for p in m: if GOAL//p <= 1: break count += len(primes[p: GOAL//p]) return count
def problem179a(): GOAL = 10**5 #checker = primes(save=True,initial=False) primes = rwh_primes2(GOAL//2) previous = 0 # counting 2 count = 1 for n in range(3,GOAL): # If it n+1 is prime, we can skip this number if isPrime(n): sig = 2 else: sig = sigma(n,primes) if sig == previous: count += 1 previous = sig return count