Tables of imaginary quadratic fields with small class numbers

class number 1

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

3,4,7,8,11,19,43,67,163

class number 2

From P. Ribenboim, Classical Theory of Algebraic Numbers, p. 636, Springer 2001

Note: The following are the squarefree d, not field discriminants
5,6,10,13,15,22,35,37,51,58,91,115,123,187,235,267,403,427

class number 3

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

23,31,59,83,107,139,211,283,
307,331,379,499,547,643,883,907

class number 4

From Steve Arno, The imaginary quadratic fields of class number 4, Acta Arith. 60 (1992) 321-334

Note: The following are the squarefree d, not field discriminants
14,17,21,30,33,34,39,42,46,55,
57,70,73,78,82,85,93,97,102,130,
133,142,155,177,190,193,195,203,219,253,
259,291,323,355,435,483,555,595,627,667,
715,723,763,795,955,1003,1027,1227,1243,1387,1411,1435,1507,1555.

class number 5

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

47,79,103,127,131,179,227,347,443,
523,571,619,683,691,739,787,947,1051,
1123,1723,1747,1867,2203,2347,2683

class number 6

From Christian Wagner, Class number 5,6 and 7, Mathematics of Computation, 65 (1996) 785-800

Note: The following are field discriminants
87,104,116,152,212,244,247,339,411,424,436,451,472,515,628,707,
771,808,835,843,856,1048,1059,1099,1108,1147,1192,1203,1219,1267,
1315,1347,1363,1432,1563,1588,1603,1843,1915,1963,2227,2283,2443,
2515,2563,2787,2923,3235,3427,3523,3763.

class number 7

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

71,151,223,251,463,467,487,587,811,
827,859,1163,1171,1483,1523,1627,1787,1987,
2011,2083,2179,2251,2467,2707,3019,3067,3187,
3907,4603,5107,5923

class number 9

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

199,367,419,491,563,823,1087,1187,1291,
1423,1579,2003,2803,3163,3259,3307,3547,3643,
4027,4243,4363,4483,4723,4987,5443,6043,6427,
6763,6883,7723,8563,8803,9067,10627

class number 11

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

167,271,659,967,1283,1303,1307,1459,
1531,1699,2027,2267,2539,2731,2851,2971,
3203,3347,3499,3739,3931,4051,5179,5683,
6163,6547,7027,7507,7603,7867,8443,9283,
9403,9643,9787,10987,13003,13267,14107,14683,
15667

class number 13

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

191,263,607,631,727,1019,1451,1499,
1667,1907,2131,2143,2371,2659,2963,3083,
3691,4003,4507,4643,5347,5419,5779,6619,
7243,7963,9547,9739,11467,11587,11827,11923,
12043,14347,15787,16963,20563

class number 15

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

239,439,751,971,1259,1327,1427,1567,
1619,2243,2647,2699,2843,3331,3571,3803,
4099,4219,5003,5227,5323,5563,5827,5987,
6067,6091,6211,6571,7219,7459,7547,8467,
8707,8779,9043,9907,10243,10267,10459,10651,
10723,11083,11971,12163,12763,13147,13963,14323,
14827,14851,15187,15643,15907,16603,16843,17467,
17923,18043,18523,19387,19867,20707,22003,26203,
27883,29947,32323,34483

class number 17

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

383,991,1091,1571,1663,1783,2531,3323,
3947,4339,4447,4547,4651,5483,6203,6379,
6451,6827,6907,7883,8539,8731,9883,11251,
11443,12907,13627,14083,14779,14947,16699,17827,
18307,19963,21067,23563,24907,25243,26083,26107,
27763,31627,33427,36523,37123

class number 19

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

311,359,919,1063,1543,1831,2099,2339.
2459,3343,3463,3467,3607,4019,4139,4327,
5059,5147,5527,5659,6803,8419,8923,8971,
9619,10891,11299,15091,15331,16363,16747,17011,
17299,17539,17683,19507,21187,21211,21283,23203,
24763,26227,27043,29803,31123,37507,38707

class number 21

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

431,503,743,863,1931,2503,2579,2767,
2819,3011,3371,4283,4523,4691,5011,5647,
5851,5867,6323,6691,7907,8059,8123,8171,
8243,8387,8627,8747,9091,9187,9811,9859,
10067,10771,11731,12107,12547,13171,13291,13339,
13723,14419,14563,15427,16339,16987,17107,17707,
17971,18427,18979,19483,19531,19819,20947,21379,
22027,22483,22963,23227,23827,25603,26683,27427,
28387,28723,28867,31963,32803,34147,34963,35323,
36067,36187,39043,40483,44683,46027,49603,51283,
52627,55603,58963,59467,61483

class number 23

From S. Arno, M.L. Robinson, F.S. Wheeler, Imaginary quadratic fields with small odd class number, Acta Arith. 83 (1998) 295-330

647,1039,1103,1279,1447,1471,1811,1979,
2411,2671,3491,3539,3847,3923,4211,4783,
5387,5507,5531,6563,6659,6703,7043,9587,
9931,10867,10883,12203,12739,13099,13187,15307,
15451,16267,17203,17851,18379,20323,20443,20899,
21019,21163,22171,22531,24043,25147,25579,25939,
26251,26947,27283,28843,30187,31147,31267,32467,
34843,35107,37003,40627,40867,41203,42667,43003,
45427,45523,47947,90787

Last modified 4th December 2007