A005474 - OEIS

A005474

Class numbers of quadratic fields.
(Formerly M2215)

1, 1, 1, 1, 1, 3, 1, 3, 5, 3, 3, 7, 3, 5, 7, 3, 3, 5, 9, 7, 3, 5, 5, 15, 9, 19, 5, 13, 9, 9, 5, 19, 9, 5, 7, 15, 13, 9, 9, 15, 25, 13, 9, 27, 19, 15, 21, 7, 13, 11, 23, 9, 13, 13, 11, 33, 15, 25, 23, 15, 13

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OFFSET

1,6

REFERENCES

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..61.

D. Shanks, The simplest cubic fields, Math. Comp., 28 (1974), 1137-1152.

Index entries for sequences related to quadratic fields

CROSSREFS

Sequence in context: A110091 A263051 A284130 * A012264 A063198 A122582

Adjacent sequences: A005471 A005472 A005473 * A005475 A005476 A005477

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved