Sisyphus sequence: Difference between revisions

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===Extreme stretch===

Using Python bindings for the primesieve C++ library and PyPy 3.9 instead of CPython (PyPy is nearly twice as fast up to s(100,000,000)), this completed in about 1 hour and 53 minutes on a AMD Ryzen 5 1500X. Memory usage was minimal thanks to <code>primesieve.Iterator()</code>.

<syntaxhighlight lang="python">import primesieve

def sisyphus36():

primes = primesieve.Iterator()

n = 1

p = 0

i = 1

while True:

i += 1

if n % 2:

p = primes.next_prime()

n = n + p

else:

n = n // 2

if n == 36:

print(f"{i:,}, {n:,}, {p:,}")

break

if __name__ == "__main__":

sisyphus36()

</syntaxhighlight>

{{out}}

<pre>

$ time pypy3.9 sisyphus_36.py

77,534,485,877, 36, 677,121,348,413

real 113m2.636s

user 112m56.973s

sys 0m0.060s