A102264 Smallest prime for which 2^n exactly divides the class number h(-4p).

5, 17, 41, 257, 521, 4481, 9521, 21929, 72089

Offset

1,1

Links

Table of n, a(n) for n=1..9.

H. Cohn and J. C. Lagarias, On the existence of fields governing the 2-invariants of the classgroup of Q(sqrt{dp}) as p varies, Math. Comp. 41 (1983), 711-730.

S. Louboutin, L-functions and class numbers of imaginary quadratic fields and of quadratic extensions of an imaginary quadratic field, Math. Comp. 59 (1992) 213-230, Table 1

Crossrefs

Sequence in context: A111268 A346706 A106973 * A122035 A052350 A318826

Adjacent sequences: A102261 A102262 A102263 * A102265 A102266 A102267

Keyword

nonn,more

Author

N. J. A. Sloane, Feb 19 2005

Status

approved