21 lines
544 B
Python
21 lines
544 B
Python
|
def pentagonal(n):
|
||
|
|
return n * (3 * n - 1) // 2
|
||
|
|
|
||
|
|
|
||
|
|
def euler_044():
|
||
|
|
n = 10000
|
||
|
|
p = [pentagonal(n) for n in range(1, n)]
|
||
|
|
p_set = set(p)
|
||
|
|
for i in range(1, n):
|
||
|
|
for j in range(i + 1, n):
|
||
|
|
if p[i - 1] + p[j - 1] in p_set and p[j - 1] - p[i - 1] in p_set:
|
||
|
|
d = pentagonal(j) - pentagonal(i)
|
||
|
|
s = d
|
||
|
|
# print("i = {}, j = {}, d = {}.".format(i, j, d))
|
||
|
|
return s
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
print("e044.py: " + str(euler_044()))
|
||
|
|
assert(euler_044() == 5482660)
|