def p021(N=10**4):
table = [numty.sigma(f) - n for (n, f) in enumerate(utils.factortable(N))]
acc = 0
for n in range(1, N):
if 0 < table[n] < N and table[table[n]] == n and table[n] != n:
logger.debug('%d %d' % (n, table[n]))
acc += n
return acc
def p021(N=10 ** 4):
table = [numty.sigma(f) - n for (n, f) in enumerate(utils.factortable(N))]
acc = 0
for n in range(1, N):
if 0 < table[n] < N and table[table[n]] == n and table[n] != n:
logger.debug("%d %d" % (n, table[n]))
acc += n
return acc
def p095(N=10**6):
table = [numty.sigma(f)-n for n,f in enumerate(utils.factortable(N))]
lengths = [-1 for n in table]
for i in range(len(table)):
chain = [i]
j=table[i]
while j < len(table) and j not in chain:
chain.append(j)
j = table[j]
if j == i:
lengths[i] = len(chain)
return lengths.index(max(lengths))
def p095(N=10**6):
table = [numty.sigma(f) - n for n, f in enumerate(utils.factortable(N))]
lengths = [-1 for n in table]
for i in range(len(table)):
chain = [i]
j = table[i]
while j < len(table) and j not in chain:
chain.append(j)
j = table[j]
if j == i:
lengths[i] = len(chain)
return lengths.index(max(lengths))
def p023():
abundant = [n for (n,f) in enumerate(numty.factortable(LIMIT))
if numty.sigma(f) > 2*n > 0]
abundantset = set(abundant)
def check_n(n):
for a in abundant:
if n-a in abundantset:
return False
if n-a < a:
return True
return sum(n for n in range(LIMIT+1) if check_n(n))
def p023():
abundant = [
n for (n, f) in enumerate(numty.factortable(LIMIT))
if numty.sigma(f) > 2 * n > 0
]
abundantset = set(abundant)
def check_n(n):
for a in abundant:
if n - a in abundantset:
return False
if n - a < a:
return True
return sum(n for n in range(LIMIT + 1) if check_n(n))