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A361075
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Products of exactly 7 distinct odd primes.
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1
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4849845, 5870865, 6561555, 7402395, 7912905, 8273265, 8580495, 8843835, 9444435, 10015005, 10140585, 10465455, 10555545, 10705695, 10818885, 10975965, 11565015, 11696685, 11996985, 12267255, 12777765, 12785955, 13096545, 13408395, 13498485, 13528515, 13667745, 13803405
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OFFSET
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1,1
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LINKS
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EXAMPLE
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a(1) = 4849845 = 3*5*7*11*13*17*19
a(9663) = 253808555 = 5*7*11*13*17*19*157
a(9961) = 258573315 = 3*5*7*11*13*17*1013
a(10000) = 259173915 = 3*5*7*11*13*41*421
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PROG
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(Python)
import numpy
from sympy import nextprime, sieve, primepi
k_upto = 14 * 10**6
array = numpy.zeros(k_upto, dtype="i4")
sieve_max_number = primepi(nextprime(k_upto // 255255))
for s in range(2, sieve_max_number):
array[sieve[s]:k_upto][::sieve[s]] += 1
for s in range(2, sieve_max_number):
array[sieve[s]**2:k_upto][::sieve[s]**2] = 0
print([k for k in range(1, k_upto, 2) if array[k] == 7])
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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