This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A081364 #11 Feb 16 2025 08:32:48 %S A081364 5,40,229,145,401,697,577,904,1129,3129,1297,2920,8101,6097,11321, %T A081364 2305,11257,7465,15409,3601,7057,19048,23593,15529,27689,13321,8761, %U A081364 21505,49281,11665,97753,29665,61889,44065,25601,35113,24337,54569 %N A081364 Smallest d such that real quadratic field with discriminant d has class number n. %H A081364 Victor Y. Wang, <a href="http://arxiv.org/abs/1508.06552">On Hilbert 2-class fields and 2-towers of imaginary quadratic number fields</a>, arXiv preprint arXiv:1508.06552, 2015 %H A081364 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/ClassNumber.html">Class Number</a> %Y A081364 Cf. A081363. %K A081364 nonn %O A081364 1,1 %A A081364 _Dean Hickerson_, Mar 19 2003 %E A081364 a(31) to a(38) from _Eric W. Weisstein_, May 19 2004