A196923 Values of fundamental discriminant -d where number of ideal classes Q(sqrt(-d)) is at most two.

3, 4, 7, 8, 11, 15, 19, 20, 24, 35, 40, 43, 51, 52, 67, 88, 91, 115, 123, 148, 163, 187, 232, 267, 403, 427

Offset

1,1

Comments

Equals A014602 union A014603. - Michel Marcus, Nov 02 2013

Links

Table of n, a(n) for n=1..26.

A. Schinzel, Solution to a Problem of Lubelski and an Improvement of a Theorem of His, Bull. Pol. Acad. Sci. Math. Vol. 59 No 2 2011 pp. 115-119.

H. M. Stark, On complex quadratic fields with class number two, Math. Comp. 29, 1975, pp. 289-302.

Crossrefs

Sequence in context: A179016 A003657 A003644 * A192051 A033195 A050032

Adjacent sequences: A196920 A196921 A196922 * A196924 A196925 A196926

Keyword

nonn,fini,full

Author

Artur Jasinski, Oct 07 2011

Status

approved