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A069654
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a(1) = 1; for n > 1, a(n) = smallest number > a(n-1) having exactly n divisors.
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3
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1, 2, 4, 6, 16, 18, 64, 66, 100, 112, 1024, 1035, 4096, 4288, 4624, 4632, 65536, 65572, 262144, 262192, 263169, 269312, 4194304, 4194306, 4477456, 4493312, 4498641, 4498752, 268435456, 268437200, 1073741824, 1073741830, 1088472064, 1089142784, 1107225625
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OFFSET
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1,2
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LINKS
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PROG
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(PARI) print(1" "1); N=1; for(n=2, 28, while(numdiv(N)!=n, N++); print(n" "N)) \\ Charles R Greathouse IV, Sep 08 2021
(Python)
from sympy import divisor_count
from itertools import count, islice
def agen(an=1, startn=1):
for n in count(startn):
while divisor_count(an) != n: an += 1
yield an
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CROSSREFS
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If "exactly" is changed to "at least", we get A072121.
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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