A003636 Number of classes per genus in quadratic field with discriminant -n. (Formerly M2213)

1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 3, 1, 2, 1, 1, 5, 1, 1, 2, 2, 3, 1, 2, 7, 5, 3, 1, 3, 1, 1, 4, 5, 3, 3, 4, 1, 3, 5, 1, 1, 5, 5, 1, 2, 3, 5, 1, 7, 3, 2, 5, 1, 4, 11, 1, 5, 4, 2, 1, 13, 1, 9, 2, 3, 3, 7, 2, 7, 5, 1, 3, 1, 1, 15, 3, 3, 4, 7, 3, 2, 2, 13, 2, 1, 11, 2, 1, 3, 7, 2, 2, 4, 5, 4, 5, 3, 2, 19, 1, 5, 2, 6

Offset

3,9

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=3..104.

Rick L. Shepherd, Binary quadratic forms and genus theory, Master of Arts Thesis, University of North Carolina at Greensboro, 2013.

Crossrefs

Sequence in context: A375117 A331286 A272880 * A353415 A078929 A030728

Adjacent sequences: A003633 A003634 A003635 * A003637 A003638 A003639

Keyword

nonn

Author

N. J. A. Sloane, Mira Bernstein

Status

approved