A089607 - OEIS

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A089607

a(n)=((-1)^(n+1)*A002425(n)) modulo 4.

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

	OFFSET	`1,2`
	FORMULA	`a(1)=1; for n>=2, a(n) = 2*A014577(n-1)+1`
	PROG	`(PARI) a(n)=numerator(2/n(4^n-1)bernfrac(2*n))%4`
	CROSSREFS	`Cf. A056832.` `Sequence in context: A124814 A122567 A122431 * A050141 A132752 A131241` `Adjacent sequences: A089604 A089605 A089606 * A089608 A089609 A089610`
	KEYWORD	`nonn`
	AUTHOR	`Benoit Cloitre (benoit7848c(AT)orange.fr), Dec 30 2003`

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Last modified February 14 05:09 EST 2012. Contains 205570 sequences.