def f():
for n in count(1):
pn = pentagonal(n)
lower_pentagonals = [pentagonal(i) for i in range(1, n)]
for p in lower_pentagonals:
if pn - p in Pentagonals and pn + p in Pentagonals:
return pn - p
def main():
t_index = 285
p_index = 165
h_index = 143
pentagonal = euler.pentagonal(p_index)
hexagonal = euler.hexagonal(h_index)
while True:
t_index += 1
triangular = euler.triangular(t_index)
if triangular > pentagonal:
p_index += 1
pentagonal = euler.pentagonal(p_index)
if triangular > hexagonal:
h_index += 1
hexagonal = euler.hexagonal(h_index)
if triangular == pentagonal == hexagonal:
break
return triangular
def main():
lst = [euler.pentagonal(i) for i in range(100000)]
s = set(lst)
for k in range(1, 100000):
penta_k = lst[k]
for j in range(1, k):
penta_j = lst[j]
if penta_k - penta_j in s:
if penta_k + penta_j in s:
return penta_k - penta_j
return 0
from itertools import count, takewhile from euler import pentagonal, is_pentagonal result = () pentagonals_generated = set() for n in count(1): pentagon_n = pentagonal(n) pentagonals_generated.add(pentagon_n) for pentagon_sub_n in takewhile(lambda p_sub_n: p_sub_n < pentagon_n, pentagonals_generated): pentagon_diff = pentagon_n - pentagon_sub_n if pentagon_diff in pentagonals_generated: pentagon_sum = pentagon_n + pentagon_sub_n if is_pentagonal(pentagon_sum): result = (pentagon_diff, n, pentagon_n, pentagon_sub_n, pentagon_sum) break else: continue break print "D: %d, n: %d, pentagon_n: %d, pentagon_sub_n: %d, pentagon_sumb: %d" % result
from itertools import count from euler import pentagonal, is_pentagonal result = () for n in count(1): pentagon_n = pentagonal(n) for sub_n in xrange(1, n): pentagon_sub_n = pentagonal(sub_n) pentagon_diff = pentagon_n - pentagon_sub_n if is_pentagonal(pentagon_diff): pentagon_sum = pentagon_n + pentagon_sub_n if is_pentagonal(pentagon_sum): result = (pentagon_diff, n, sub_n, pentagon_n, pentagon_sub_n, pentagon_sum) break else: continue break print "D: %d, n: %d, sub_n: %d, pentagon_n: %d, pentagon_sub_n: %d, pentagon_sumb: %d" % result
