A123563 Discriminants of imaginary quadratic fields with class number 20 (negated).

455, 615, 776, 824, 836, 920, 1064, 1124, 1160, 1263, 1284, 1460, 1495, 1524, 1544, 1592, 1604, 1652, 1695, 1739, 1748, 1796, 1880, 1887, 1896, 1928, 1940, 1956, 2136, 2247, 2360, 2404, 2407, 2483, 2487, 2532, 2552

Offset: 1

Author

Eric W. Weisstein, Nov 19 2006

Keywords

• nonn
• fini

Comments

A finite sequence with exactly 350 terms.

Links

• Eric Weisstein's World of Mathematics, Class Number.

Crossrefs

Cf. A006203, A013658, A014602, A014603, A046002, ..., A046016, A046018, A046020.

Programs

Mathematica

Reap[ For[n = 1, n < 3000, n++, s = Sqrt[-n]; If[ NumberFieldClassNumber[s] == 20, d = -NumberFieldDiscriminant[s]; Print[d]; Sow[d]]]][[2, 1]] // Union (* Jean-François Alcover, Oct 05 2012 *)