id:A094473 - OEIS Search Results

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Smallest prime factor of 2^n+3^n.

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5, 13, 5, 97, 5, 13, 5, 17, 5, 13, 5, 97, 5, 13, 5, 3041, 5, 13, 5, 41, 5, 13, 5, 17, 5, 13, 5, 97, 5, 13, 5, 1153, 5, 13, 5, 97, 5, 13, 5, 17, 5, 13, 5, 89, 5, 13, 5, 193, 5, 13, 5, 97, 5, 13, 5, 17, 5, 13, 5, 41, 5, 13, 5, 769, 5, 13, 5, 97, 5, 13, 5, 17, 5, 13, 5 (list; graph; listen)

	OFFSET	`1,1`
	EXAMPLE	`If n=4k+1 or 4k+3 then 2^n+3^n is divisible by 5.` `If n=4k+2 then 2^n+3^n is divisible by 13.` `Case n=4k including especially n=2^j cannot be` `discussed with elementary tools and primality of` `2^n+3^n remains open.`
	MATHEMATICA	`mif[x_]:=Part[Flatten[FactorInteger[x]], 1] Table[mif[2^w+3^w], {w, 1, 75}]`
	CROSSREFS	`Cf. A082101, A094474-A094494.` `Sequence in context: A121645 A057691 A089619 this_sequence A068530 A088315 A138296` `Adjacent sequences: A094470 A094471 A094472 this_sequence A094474 A094475 A094476`
	KEYWORD	`nonn`
	AUTHOR	`Labos E. (labos(AT)ana.sote.hu), Jun 02 2004`

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Last modified July 26 23:19 EDT 2008. Contains 142293 sequences.

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