A106032 a(n) is the number of orbits under the action of GL_2[Z] on the primitive binary quadratic forms of discriminant D, where D>1 is the n-th fundamental discriminant.

1, 1, 2, 1, 1, 2, 2, 2, 1, 2, 1, 2, 1, 2, 1, 2, 2, 4, 1, 2, 2, 1, 2, 2, 2, 2, 1, 2, 2, 1, 1, 2, 4, 1, 1, 4, 2, 2, 2, 3, 1, 4, 2, 3, 1, 2, 4, 1, 2, 4, 4, 2, 1, 2, 1, 2, 2, 2, 1

Offset

1,3

Comments

A003646 is the same except it is under the action of SL_2[Z].

Links

Table of n, a(n) for n=1..59.

S. R. Finch, Class number theory

Steven R. Finch, Class number theory [Cached copy, with permission of the author]

Jens Jonasson, Classes of integral binary quadratic forms, Master's thesis (2001), Appendix B.

Example

D = 5, 8, 12, 13, 17, 21, 24, 28, ..., that is, A003658.

Crossrefs

Cf. A003658, A003646.

Sequence in context: A336498 A102418 A317989 * A003646 A201503 A112758

Adjacent sequences: A106029 A106030 A106031 * A106033 A106034 A106035

Keyword

nonn

Author

Steven Finch, May 05 2005

Status

approved