55 lines
1.2 KiB
Python
55 lines
1.2 KiB
Python
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#!/usr/bin/env python3
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from lib import primegen
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from math import log
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from operator import mul
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from functools import reduce
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def calc(pows):
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return (reduce(mul, (2*p + 1 for p in pows)) + 1) // 2
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def increment(i, pows):
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n = 0
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if i < len(pows):
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n = pows[i]
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return [n + 1] * (i+1) + pows[i+1:]
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def val(pows):
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return sum(p*v for p, v in zip(pows, vals))
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def fpwof2(pows, n):
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if len(pows) == 1:
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return n-1
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r = (2*n - 1) // reduce(mul, (2*p + 1 for p in pows[1:]))
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r = (r - 1) // 2
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while calc([r] + pows[1:]) < n:
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r += 1
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return r
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N = 10 ** 3
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primes = list(primegen(100))
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vals = [log(p) / log(2) for p in primes]
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i = 0
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pows = [0]
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best = fpwof2(pows, N)
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best_pows = None
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while not (val(pows) >= best and sum(pows) == len(pows)):
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if not i:
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pows[0] = fpwof2(pows, N)
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if len(pows) > 1 and pows[0] < pows[1]:
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pows[0] = pows[1]
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if val(pows) < best:
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best = val(pows)
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best_pows = pows
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i = 1
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pows = increment(i, pows)
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if val(pows) >= best:
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i += 1
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else:
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i = 0
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print(reduce(mul, (n**pw for n, pw in zip(primes, best_pows))))
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