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A003647 Class number of real quadratic forms with discriminant 4n+1.
(Formerly M0084)
1
1, 1, 1, 2, 1, 2, 1, 1, 1, 2, 1, 2, 2, 1, 2, 2, 1, 2, 1, 1, 4, 1, 1, 2, 2, 1, 2, 4, 1, 1, 2, 4, 1, 2, 1, 2, 1, 1, 2, 4, 2, 2, 2, 4, 3, 1, 2, 1, 2, 2, 3, 2, 1, 4, 1, 1, 4, 1, 2, 4, 2, 1, 1, 6, 2, 1, 2, 4, 1, 1, 4, 2, 1, 4, 2, 4, 1, 2, 1, 5, 1, 2, 2, 1, 4, 1, 2, 4, 1, 2, 1, 1, 4, 6, 6, 2, 2, 2, 2, 2, 2, 8, 1, 2, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,4
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
CROSSREFS
Cf. A003648.
Sequence in context: A214713 A049046 A227945 * A353352 A084217 A245548
KEYWORD
nonn
AUTHOR
STATUS
approved

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Last modified March 28 18:04 EDT 2024. Contains 371254 sequences. (Running on oeis4.)