id:A087274 - OEIS Search Results

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Prime index of largest prime factor of 3*prime[n]+1.

+0
3

4, 3, 1, 5, 7, 3, 6, 10, 4, 5, 15, 4, 11, 6, 20, 3, 24, 9, 26, 28, 5, 7, 3, 19, 21, 8, 11, 9, 13, 7, 43, 45, 27, 8, 4, 49, 17, 4, 54, 6, 57, 7, 13, 10, 12, 9, 66, 19, 11, 14, 4, 72, 42, 10, 44, 22, 26, 12, 6, 47, 7, 5, 89, 91, 15, 7, 20, 9, 98, 32, 16, 5, 10, 4, 104, 9, 21, 35, 14, 63, 12, 22 (list; graph; listen)

	OFFSET	`1,1`
	FORMULA	`a(n)=A000720[A006530[1+3.A000040[n]]]`
	EXAMPLE	`n=10:p(10)=29, max-p-factor[88]=11,pi[11]=4=a(n)<n;` `n=11:p(11)=31, max-p-factor[94]=47,pi[47]=15=a(n)>n;`
	MATHEMATICA	`ffi[x_] := Flatten[FactorInteger[x]] ma[x_] := Part[Reverse[ffi[x]], 2] Table[PrimePi[ma[3*Prime[w]+1]], {w, 1, 100}]`
	CROSSREFS	`Cf. A000720, A006530, A087272, A087273.` `Sequence in context: A016499 A066204 A020839 this_sequence A103552 A127673 A016698` `Adjacent sequences: A087271 A087272 A087273 this_sequence A087275 A087276 A087277`
	KEYWORD	`nonn`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu), Sep 18 2003`

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Last modified July 25 07:41 EDT 2008. Contains 142293 sequences.

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