A003642 - OEIS

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A003642

Number of genera of quadratic field with discriminant -4n, where -n == 2 or 3 (mod 4).
(Formerly M0211)

1, 1, 2, 2, 2, 2, 2, 2, 4, 2, 2, 2, 4, 4, 2, 2, 2, 2, 4, 2, 2, 4, 2, 2, 2, 4, 4, 4, 4, 2, 2, 4, 4, 2, 4, 2, 2, 4, 2, 2, 2, 4, 8, 2, 2, 4, 2, 4, 2, 2, 4, 4, 4, 2, 2, 4, 4, 2, 4, 2, 2, 4, 2, 2, 4, 8, 2, 4, 2, 4, 4, 2, 2, 4, 4, 4, 4, 2, 2, 2, 4, 2, 4, 2, 4, 8, 4, 2, 4, 2, 4, 4, 2, 2, 4, 2, 4, 4, 2, 4, 4, 4, 2, 2, 4 (list; graph; refs; listen; history; internal format)

	OFFSET	`1,3`
	REFERENCES	`D. A. Buell, Binary Quadratic Forms. Springer-Verlag, NY, 1989, pp. 224-241.` `N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).`
	LINKS	`Index entries for sequences related to quadratic fields`
	CROSSREFS	`Cf. A003641.` `Sequence in context: A027388 A083261 A003648 * A100007 A104369 A051702` `Adjacent sequences: A003639 A003640 A003641 * A003643 A003644 A003645`
	KEYWORD	`nonn`
	AUTHOR	`N. J. A. Sloane (njas(AT)research.att.com), Mira Bernstein`

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Last modified February 16 01:56 EST 2012. Contains 205860 sequences.