A102368 - OEIS

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A102368

Smallest k>0 such that n^k + 1 is not prime.

3, 1, 3, 1, 3, 1, 1, 1, 3, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 3, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 2, 1, 2, 1, 1, 1, 2 (list; graph; refs; listen; history; internal format)

	OFFSET	`2,1`
	COMMENTS	`a(odd) = 1.`
	EXAMPLE	`n=10: 10^1+1=11=A000040(5), 10^2+1=101=A000040(26), but 10^3+1=1001=71113, therefore a(10)=3.`
	CROSSREFS	`Sequence in context: A201681 A062174 A154754 * A063062 A066056 A153284` `Adjacent sequences: A102365 A102366 A102367 * A102369 A102370 A102371`
	KEYWORD	`nonn`
	AUTHOR	`Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Feb 22 2005`

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Last modified February 14 13:08 EST 2012. Contains 205623 sequences.