A099301 - OEIS

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A099301

Arithmetic derivative of d(n), the number of divisors of n.

0, 1, 1, 1, 1, 4, 1, 4, 1, 4, 1, 5, 1, 4, 4, 1, 1, 5, 1, 5, 4, 4, 1, 12, 1, 4, 4, 5, 1, 12, 1, 5, 4, 4, 4, 6, 1, 4, 4, 12, 1, 12, 1, 5, 5, 4, 1, 7, 1, 5, 4, 5, 1, 12, 4, 12, 4, 4, 1, 16, 1, 4, 5, 1, 4, 12, 1, 5, 4, 12, 1, 16, 1, 4, 5, 5, 4, 12, 1, 7, 1, 4, 1, 16, 4, 4, 4, 12, 1, 16, 4, 5, 4, 4, 4, 16, 1, 5 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,6`
	REFERENCES	`See A003415`
	FORMULA	`a(n) = A003415(A000005(n))`
	MATHEMATICA	`dn[0]=0; dn[1]=0; dn[n_]:=Module[{f=Transpose[FactorInteger[n]]}, If[PrimeQ[n], 1, Plus@@(n*f[[2]]/f[[1]])]]; Table[dn[DivisorSigma[0, n]], {n, 150}]`
	CROSSREFS	`Cf. A003415 (arithmetic derivative of n).` `Sequence in context: A080905 A010685 A174571 * A050347 A126114 A074393` `Adjacent sequences: A099298 A099299 A099300 * A099302 A099303 A099304`
	KEYWORD	`nonn`
	AUTHOR	`T. D. Noe (noe(AT)sspectra.com), Oct 12 2004`

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Last modified February 14 20:38 EST 2012. Contains 205663 sequences.