A083341 - OEIS

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A083341

Smaller factor of the n-th semiprime of the form (m!)^2+1.

13, 101, 17, 1344169, 149, 9049, 37, 710341, 2122590346576634509, 171707860473207588349837, 7686544942807799800864250520468090636146175134909, 2196283505473 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	LINKS	`Andrew Walker, Table of factors of (n!)^2+1.`
	FORMULA	`Numbers p such that p*q=(A083340(n)!)^2+1, p, q prime, p<q`
	EXAMPLE	`a(1)=13 because (A083340(1)!)^2+1=518401=13*39877`
	CROSSREFS	`Cf. A083340, A020549.` `Sequence in context: A155646 A089936 A196928 * A075604 A142297 A131021` `Adjacent sequences: A083338 A083339 A083340 * A083342 A083343 A083344`
	KEYWORD	`nonn`
	AUTHOR	`Hugo Pfoertner (hugo(AT)pfoertner.org), Apr 25 2003`
	EXTENSIONS	`The 11-th term of the sequence (49-digit factor of the 100 digit number (41!)^2+1 was found with Yuji Kida's multiple polynomial quadratic sieve UBASIC PPMPQS v3.5 in 13 days CPU time on an Intel PIII 550 Mhz.`

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Last modified February 17 21:13 EST 2012. Contains 206085 sequences.