A108893 - OEIS

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A108893

Difference of primes pairs alternating between form 4k+3 and 4k+1.

4, 4, 4, 4, 4, 8, 4, 4, 4, 4, 12, 4, 4, 4, 8, 8, 4, 8, 4, 12, 12, 12, 8, 8, 8, 4, 4, 4, 4, 4, 4, 8, 4, 12, 4, 4, 8, 8, 4, 4, 4, 8, 4, 4, 8, 4, 12, 4, 8, 4, 4, 24, 4, 12, 12, 4, 8, 4, 4, 12, 4, 16, 24, 8, 4, 4, 4, 4, 12, 4, 12, 4, 8, 16, 4, 4, 8, 8, 16, 4, 8, 4, 8, 8, 12, 4, 28, 4, 12, 20, 4, 12, 4, 8 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,1`
	COMMENTS	`a(n)>=4 because prime p and prime p + 2 (twin primes) are never at the same time of the form 4k+3 or 4k+1.`
	FORMULA	`a(n) = A108811(2n) - A108811(2n-1).`
	EXAMPLE	`a(1)=4 because the difference primes pairs of form 4k+3 11 and 7 = 4;` `a(2)=4 because the difference primes pairs of form 4k+1 17 and 13 = 4.`
	CROSSREFS	`Cf. A108811, increasing consecutive prime pairs alternating between form 4k+3 and 4k+1.` `Sequence in context: A059190 A085142 A064053 * A162281 A048760 A035627` `Adjacent sequences: A108890 A108891 A108892 * A108894 A108895 A108896`
	KEYWORD	`easy,nonn`
	AUTHOR	`Giovanni Teofilatto (g.teofilatto(AT)tiscalinet.it), Jul 15 2005`
	EXTENSIONS	`Extended by Ray Chandler (rayjchandler(AT)sbcglobal.net), Jul 21 2005`

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Last modified February 15 13:31 EST 2012. Contains 205802 sequences.