A003637 - OEIS

A003637

Number of classes per genus in quadratic field with discriminant -4n+1.
(Formerly M2263)

1, 1, 1, 1, 1, 3, 3, 1, 2, 1, 5, 1, 2, 3, 1, 7, 5, 3, 3, 1, 4, 5, 3, 4, 1, 5, 1, 5, 5, 3, 5, 7, 2, 5, 1, 11, 5, 4, 1, 13, 1, 9, 2, 3, 7, 2, 7, 5, 3, 1, 15, 3, 7, 3, 2, 13, 1, 11, 3, 7, 2, 4, 4, 5, 3, 19, 5, 2, 6, 3, 9, 3, 5, 2, 19, 9, 4, 3, 17, 7, 4, 4, 1, 8, 3, 5, 9, 1, 21, 1, 15, 5, 7, 3, 5, 7, 7, 8, 25

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,6

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

Table of n, a(n) for n=1..99.

CROSSREFS

Cf. A003638.

Sequence in context: A368339 A244328 A073067 * A317413 A359838 A110628

Adjacent sequences: A003634 A003635 A003636 * A003638 A003639 A003640

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Mira Bernstein

STATUS

approved