A035115 Relative class number h- of cyclotomic field Q(zeta_m) where m is n-th term of A035113.

1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 3, 1, 2, 1, 3, 2, 3, 1, 8, 9, 5, 17, 8, 5, 9, 4, 37, 9, 7, 19, 19, 121, 10, 11, 55, 55, 11, 211, 43, 69, 201, 695, 64, 351, 13, 468, 39, 507, 156, 84, 75, 4889, 2593, 1536, 10752, 41241, 76301, 1280, 6795

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• nice

References

• L. C. Washington, Introduction to Cyclotomic Fields, Springer, p. 353.

Crossrefs

Cf. A000010, A035113, A035114, A055513, A061494, A061653.

Programs

Mathematica

(* This is only a recomputation of the existing data. *)
terms = 76;
A035113 = Sort[Select[Range[3 terms], Mod[#, 4] != 2&], EulerPhi[#1] <= EulerPhi[#2]&];
A061653 = Import["https://oeis.org/A061653/b061653.txt", "Table"][[All, 2]];
a[n_] := A061653[[A035113[[n]] ]];
Array[a, terms] (* Jean-François Alcover, Aug 17 2019 *)

Formula

a(n) = A061653(A035113(n)).

Extensions

Changed 41421 to 41241, value is given incorrectly in first edition of Washington, Matthew Johnson, Jul 20 2013