A057940 - OEIS

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A057940

Number of prime factors of 4^n + 1 (counted with multiplicity).

1, 1, 2, 1, 3, 2, 3, 1, 4, 2, 3, 3, 4, 2, 6, 2, 4, 4, 4, 2, 6, 3, 5, 3, 7, 3, 6, 3, 3, 4, 5, 2, 6, 4, 7, 5, 5, 4, 10, 3, 5, 5, 5, 4, 11, 2, 4, 3, 6, 6, 9, 2, 4, 6, 7, 5, 8, 3, 7, 6, 6, 4, 10, 2, 10, 7, 6, 4, 8, 4, 6, 7, 5, 2, 14, 4, 9, 5, 4, 4, 10, 4, 6, 8, 11, 4, 8, 3, 4, 8, 11, 4, 9, 5, 10, 4, 9, 8, 12, 6 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,3`
	LINKS	`S. S. Wagstaff, Jr., The Cunningham Project` `S. S. Wagstaff, Jr., Main Tables from the Cunningham Project.`
	FORMULA	`a(n) = A057957(2n) - A057957(n) - T. D. Noe (noe(AT)sspectra.com), Jun 19 2003`
	CROSSREFS	`Cf. A057934-A057941, A054992.` `Cf. A057957.` `Sequence in context: A151682 A159918 A108663 * A097285 A057432 A038568` `Adjacent sequences: A057937 A057938 A057939 * A057941 A057942 A057943`
	KEYWORD	`nonn`
	AUTHOR	`Patrick De Geest (pdg(AT)worldofnumbers.com), Oct 15 2000.`

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Last modified February 16 07:10 EST 2012. Contains 205874 sequences.