login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A003639 Number of classes per genus in Q(sqrt -n), n squarefree.
(Formerly M0085)
0
1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 3, 3, 1, 3, 1, 2, 1, 1, 3, 2, 4, 1, 1, 2, 5, 1, 3, 2, 1, 1, 3, 3, 4, 2, 2, 1, 2, 1, 7, 2, 5, 2, 1, 5, 2, 3, 1, 5, 3, 6, 1, 1, 4, 4, 2, 7, 1, 5, 1, 3, 3, 3, 3, 4, 4, 2, 1, 3, 5, 5, 1, 5, 3, 1, 5, 1, 7, 4, 2, 3, 2, 2, 5, 2, 8, 7, 7, 2, 2, 3, 4, 5, 4, 1, 1, 5, 11, 3 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,10

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..104.

CROSSREFS

Sequence in context: A128115 A091318 A198898 * A174110 A264969 A320301

Adjacent sequences:  A003636 A003637 A003638 * A003640 A003641 A003642

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Mira Bernstein

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 19 20:42 EST 2019. Contains 329323 sequences. (Running on oeis4.)