id:A112621 - OEIS Search Results

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If p^b(p,n) is the highest power of the prime p dividing n, then a(n) = sum_{p|n} b(p,n)^b(p,n).

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1, 1, 4, 1, 2, 1, 27, 4, 2, 1, 5, 1, 2, 2, 256, 1, 5, 1, 5, 2, 2, 1, 28, 4, 2, 27, 5, 1, 3, 1, 3125, 2, 2, 2, 8, 1, 2, 2, 28, 1, 3, 1, 5, 5, 2, 1, 257, 4, 5, 2, 5, 1, 28, 2, 28, 2, 2, 1, 6, 1, 2, 5, 46656, 2, 3, 1, 5, 2, 3, 1, 31, 1, 2, 5, 5, 2, 3, 1, 257, 256, 2, 1, 6, 2, 2, 2, 28, 1, 6, 2, 5, 2 (list; graph; listen)

	OFFSET	`2,3`
	FORMULA	`a(n)=1 iff n is prime, a(n)=2 iff n is a nonsquare semiprime (A006881). - Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 27 2005`
	EXAMPLE	`45 = 3^2 * 5^1. So a(45) = 2^2 + 1^1 = 5.`
	MATHEMATICA	`f[n_] := Block[{fi = Last@Transpose@FactorInteger@n}, Plus @@ (fi^fi)]; Rest@Array[f, 92] (* Robert G. Wilson v *)`
	CROSSREFS	`Adjacent sequences: A112618 A112619 A112620 this_sequence A112622 A112623 A112624` `Sequence in context: A019777 A090885 A008476 this_sequence A081448 A106437 A064215`
	KEYWORD	`nonn`
	AUTHOR	`Leroy Quet (qq-quet(AT)mindspring.com), Dec 25 2005`
	EXTENSIONS	`More terms from Robert G. Wilson v (rgwv(AT)rgwv.com), Dec 27 2005`

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Last modified October 11 13:47 EDT 2008. Contains 144830 sequences.

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