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A175462
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Number of divisors of integers of the form 5 + 8n.
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2
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2, 2, 4, 2, 2, 6, 2, 2, 4, 4, 4, 4, 2, 2, 6, 4, 4, 4, 2, 2, 8, 2, 2, 8, 2, 4, 4, 4, 2, 4, 6, 4, 6, 2, 2, 8, 2, 4, 4, 2, 6, 6, 4, 2, 8, 4, 2, 4, 2, 2, 10, 4, 2, 8, 4, 4, 4, 2, 4, 6, 4, 4, 4, 2, 4, 12, 4, 2, 6, 2, 4, 4, 4, 4, 4, 6, 2, 8, 4, 6, 8, 2, 2, 4, 2, 4, 12, 2, 2, 4, 6, 2, 8, 4, 2, 12, 2, 4, 4, 2, 8, 4, 2
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OFFSET
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0,1
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COMMENTS
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All terms are even.
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LINKS
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FORMULA
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a(n) = d(5 + 8*n).
Sum_{k=1..n} a(k) ~ (n/2) * (log(n) + 2*gamma - 1 + 5*log(2)), where gamma is Euler's constant (A001620). - Amiram Eldar, Jan 14 2024
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MAPLE
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map(numtheory:-tau, [seq(i, i=5..1000, 8)]); # Robert Israel, Mar 20 2020
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MATHEMATICA
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Table[DivisorSigma[0, 8*n + 5], {n, 0, 100}] (* Amiram Eldar, Jan 14 2024 *)
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PROG
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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