A001985 Class numbers of quadratic fields. (Formerly M2669 N1068)

3, 7, 19, 25, 51, 109, 153, 213, 289, 1121, 1121, 1121, 3997, 7457, 12017, 12719, 20299, 24503, 24503, 25817, 25817, 128755, 128755, 219207, 456929, 456929, 761619, 883537

Offset

3,1

References

D. H. Lehmer, E. Lehmer and D. Shanks, Integer sequences having prescribed quadratic character, Math. Comp., 24 (1970), 433-451.

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

Table of n, a(n) for n=3..30.

D. H. Lehmer, E. Lehmer and D. Shanks, Integer sequences having prescribed quadratic character, Math. Comp., 24 (1970), 433-451 [Annotated scanned copy]

Index entries for sequences related to quadratic fields

Crossrefs

Sequence in context: A032388 A050866 A226923 * A203321 A203319 A366171

Adjacent sequences: A001982 A001983 A001984 * A001986 A001987 A001988

Keyword

nonn,more

Author

N. J. A. Sloane

Status

approved