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A049599
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Number of (1+e)-divisors of n: if n = Product p(i)^r(i), d = Product p(i)^s(i) and s(i) = 0 or s(i) divides r(i), then d is a (1+e)-divisor of n.
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6
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1, 2, 2, 3, 2, 4, 2, 3, 3, 4, 2, 6, 2, 4, 4, 4, 2, 6, 2, 6, 4, 4, 2, 6, 3, 4, 3, 6, 2, 8, 2, 3, 4, 4, 4, 9, 2, 4, 4, 6, 2, 8, 2, 6, 6, 4, 2, 8, 3, 6, 4, 6, 2, 6, 4, 6, 4, 4, 2, 12, 2, 4, 6, 5, 4, 8, 2, 6, 4, 8, 2, 9, 2, 4, 6, 6, 4, 8, 2, 8, 4, 4, 2, 12, 4, 4, 4, 6, 2, 12, 4, 6, 4, 4, 4, 6, 2, 6, 6, 9, 2, 8, 2
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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FORMULA
| If n = Product p(i)^r(i) then a(n) = Product (tau(r(i))+1), where tau(n) = number of divisors of n, cf. A000005. - Vladeta Jovovic (vladeta(AT)eunet.rs), Apr 29 2001
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MATHEMATICA
| a[n_] := Times @@ (DivisorSigma[0, #] + 1 &) /@ FactorInteger[n][[All, 2]]; a[1] = 1; Table[a[n], {n, 1, 103}] (* From Jean-François Alcover, Oct 10 2011 *)
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CROSSREFS
| Cf. A049603, A051378.
Sequence in context: A106491 A073184 A073182 * A043261 A157986 A025479
Adjacent sequences: A049596 A049597 A049598 * A049600 A049601 A049602
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KEYWORD
| nonn,easy,nice,mult
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AUTHOR
| Yasutoshi Kohmoto (zbi74583(AT)boat.zero.ad.jp)
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EXTENSIONS
| More terms from Naohiro Nomoto (6284968128(AT)geocities.co.jp), Apr 12 2001
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