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A283659 Class numbers of the fields Q(sqrt(A283658(n)). 1
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

REFERENCES

Z. I. Borevich and I. R. Shafarevich, Number Theory. Academic Press, NY, 1966.

LINKS

Table of n, a(n) for n=1..29.

EXAMPLE

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.

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

CROSSREFS

Cf. A283658, A003649, A003172.

Sequence in context: A004045 A064418 A171164 * A032939 A030073 A115271

Adjacent sequences:  A283656 A283657 A283658 * A283660 A283661 A283662

KEYWORD

nonn,more

AUTHOR

Emmanuel Vantieghem, Mar 13 2017

STATUS

approved

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Last modified March 19 18:49 EDT 2019. Contains 321330 sequences. (Running on oeis4.)