

A003171


Discriminants of orders of imaginary quadratic fields with 1 class per genus (a finite sequence).
(Formerly M2331 N0922)


3



3, 4, 7, 8, 11, 12, 15, 16, 19, 20, 24, 27, 28, 32, 35, 36, 40, 43, 48, 51, 52, 60, 64, 67, 72, 75, 84, 88, 91, 96, 99, 100, 112, 115, 120, 123, 132, 147, 148, 160, 163, 168, 180, 187, 192, 195, 228, 232, 235, 240, 267, 280, 288, 312, 315, 340, 352, 372, 403
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

1,1


REFERENCES

Z. I. Borevich and I. R. Shafarevich, Number Theory. Academic Press, NY, 1966, pp. 425430.
L. E. Dickson, Introduction to the Theory of Numbers. Dover, NY, 1957, p. 85.
N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..101
Rick L. Shepherd, Binary quadratic forms and genus theory, Master of Arts Thesis, University of North Carolina at Greensboro, 2013.


PROG

(PARI) ok(n)={(n)%4<2 && !#select(k>k<>2, quadclassunit(n).cyc)} \\ Andrew Howroyd, Jul 20 2018


CROSSREFS

Cf. A000926, A133288.
Sequence in context: A154708 A227148 A026444 * A028970 A188259 A058235
Adjacent sequences: A003168 A003169 A003170 * A003172 A003173 A003174


KEYWORD

fini,nonn


AUTHOR

N. J. A. Sloane, Mira Bernstein


EXTENSIONS

Terms a(44) and beyond from Andrew Howroyd, Jul 20 2018


STATUS

approved



