A283659 Class numbers of the fields Q(sqrt(A283658(n))).
2, 3, 4, 8, 12, 14, 16, 20, 22, 28, 44, 48, 52, 58, 74, 96, 116, 130, 153, 154, 176, 180, 200, 230, 240, 256, 288, 296, 312, 316, 357, 394, 412, 452, 504, 540, 574, 575, 584, 616, 692, 924, 994, 1061, 1068, 1080, 1245, 1248, 1302, 1336
Offset: 1
Examples
The sequence starts with 2 because the first number in A283658 is 10 and the class number of Q(sqrt(10)) equals 2. The fifth term is 12 because A283658(5) = 226 and the class number of Q(sqrt(226)) is 12.
References
- Z. I. Borevich and I. R. Shafarevich, Number Theory. Academic Press, NY, 1966.
Programs
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Mathematica
H = {}; hx = 1; d = 2; While[hx < 5, d++; If[SquareFreeQ[d], h = NumberFieldClassNumber[Sqrt[d]]; If[h > hx, AppendTo[H, h]; hx = h]]]; H
Extensions
a(30)-a(50) from Robin Visser, May 25 2024