A079030 Least k such that the class number of quadratic order of discriminant D=-4k equals n.

1, 5, 11, 14, 47, 26, 71, 41, 59, 74, 167, 89, 191, 101, 131, 146, 383, 236, 311, 194, 251, 269, 647, 299, 479, 314, 419, 341, 887, 461, 719, 446, 659, 614, 1031, 626, 1487, 1199, 1019, 689, 1151, 794, 1847, 854, 971, 941, 3023, 1106, 1511, 1109, 1091, 1256, 2711

Offset: 1

Author

Benoit Cloitre, Feb 01 2003

Keywords

• nonn

Crossrefs

Cf. A000003.

Programs

PARI

a(n)=if(n<0,0,k=1; while(abs(n-qfbclassno(-4*k))>0,k++); k)