

A104888


Class number of binary quadratic forms with radicand A005117(n).


1



1, 2, 1, 2, 2, 2, 2, 1, 2, 4, 1, 2, 2, 2, 2, 2, 1, 4, 2, 2, 4, 4, 1, 2, 4, 1, 4, 2, 2, 2, 4, 1, 4, 2, 2, 2, 1, 2, 2, 4, 2, 2, 4, 2, 1, 2, 2, 4, 6, 4, 2, 2, 2, 4, 1, 4, 2, 2, 4, 1
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OFFSET

2,2


COMMENTS

The fundamental discriminant D and the radicand m (which is squarefree) are related via D=m if m=1 (mod 4) and D=4*m if m=2,3 (mod 4).


REFERENCES

Hua Loo Keng, Introduction to Number Theory, SpringerVerlag, 1982, pp. 465472.


LINKS

Table of n, a(n) for n=2..61.
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, Masters thesis (2001), Appendix B.


CROSSREFS

Cf. A003646, A087048.
Sequence in context: A057768 A317990 A106030 * A286885 A254885 A108461
Adjacent sequences: A104885 A104886 A104887 * A104889 A104890 A104891


KEYWORD

nonn


AUTHOR

Steven Finch, May 03 2005


STATUS

approved



