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A366577
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Number of divisors of 3^n+1.
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11
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2, 3, 4, 6, 4, 6, 8, 6, 8, 24, 12, 12, 8, 6, 16, 48, 4, 24, 16, 12, 8, 72, 16, 6, 64, 24, 16, 96, 16, 24, 48, 12, 4, 96, 16, 24, 16, 24, 16, 192, 32, 12, 128, 6, 32, 768, 16, 24, 16, 24, 128, 384, 16, 12, 32, 96, 64, 192, 16, 12, 128, 12, 32, 4608, 4, 24, 64
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OFFSET
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0,1
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LINKS
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FORMULA
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EXAMPLE
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a(4)=4 because 3^4+1 has divisors {1, 2, 41, 82}.
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MAPLE
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a:=n->numtheory[tau](3^n+1):
seq(a(n), n=0..100);
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MATHEMATICA
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DivisorSigma[0, 3^Range[0, 100]+1] (* Paolo Xausa, Oct 15 2023 *)
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PROG
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CROSSREFS
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Cf. A000005, A002592, A034472, A046798, A057935, A057941, A074476, A274909, A366575, A366578, A366579, A366580
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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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