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A046801
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Number of divisors of 2^n-1.
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29
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1, 2, 2, 4, 2, 6, 2, 8, 4, 8, 4, 24, 2, 8, 8, 16, 2, 32, 2, 48, 12, 16, 4, 96, 8, 8, 8, 64, 8, 96, 2, 32, 16, 8, 16, 512, 4, 8, 16, 192, 4, 144, 8, 128, 64, 16, 8, 768, 4, 128, 32, 128, 8, 160, 64, 256, 16, 64, 4, 4608, 2, 8, 96, 128, 8, 384, 4, 128, 16, 512, 8, 8192, 8, 32, 128
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OFFSET
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1,2
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COMMENTS
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a(0) cannot be defined because 0's divisors are an infinite set (every number is a divisor of 0.)
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LINKS
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EXAMPLE
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a(120) = 73728 since 2^120-1 has that many divisors.
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MAPLE
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a:= n-> numtheory[tau](2^n-1):
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MATHEMATICA
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PROG
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(Python)
from sympy import divisor_count
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CROSSREFS
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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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