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 A283659 #12 May 26 2024 17:58:46
%S A283659 2,3,4,8,12,14,16,20,22,28,44,48,52,58,74,96,116,130,153,154,176,180,
%T A283659 200,230,240,256,288,296,312,316,357,394,412,452,504,540,574,575,584,
%U A283659 616,692,924,994,1061,1068,1080,1245,1248,1302,1336
%N A283659 Class numbers of the fields Q(sqrt(A283658(n))).
%D A283659 Z. I. Borevich and I. R. Shafarevich, Number Theory. Academic Press, NY, 1966.
%e A283659 The sequence starts with 2 because the first number in A283658 is 10 and the class number of Q(sqrt(10)) equals 2.
%e A283659 The fifth term is 12 because A283658(5) = 226 and the class number of Q(sqrt(226)) is 12.
%t A283659 H = {}; hx = 1; d = 2; While[hx < 5, d++;
%t A283659 If[SquareFreeQ[d], h = NumberFieldClassNumber[Sqrt[d]];
%t A283659 If[h > hx, AppendTo[H, h]; hx = h]]]; H
%Y A283659 Cf. A283658, A003649, A003172.
%K A283659 nonn,more
%O A283659 1,1
%A A283659 _Emmanuel Vantieghem_, Mar 13 2017
%E A283659 a(30)-a(50) from _Robin Visser_, May 25 2024