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A366621
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Number of divisors of 6^n-1.
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11
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2, 4, 4, 8, 6, 16, 4, 16, 16, 48, 8, 128, 8, 48, 48, 64, 32, 128, 8, 384, 16, 32, 32, 512, 32, 128, 64, 384, 4, 1536, 8, 512, 64, 256, 96, 8192, 64, 64, 64, 3072, 8, 768, 32, 512, 1536, 256, 16, 8192, 32, 512, 512, 2048, 16, 2048, 96, 12288, 128, 64, 16
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OFFSET
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1,1
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LINKS
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FORMULA
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EXAMPLE
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a(4)=8 because 6^4-1 has divisors {1, 5, 7, 35, 37, 185, 259, 1295}.
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MAPLE
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a:=n->numtheory[tau](6^n-1):
seq(a(n), n=1..100);
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MATHEMATICA
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DivisorSigma[0, 6^Range[100]-1]
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PROG
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(PARI) a(n) = numdiv(6^n-1);
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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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