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A035115 Relative class number h- of cyclotomic field Q(zeta_m) where m is n-th term of A035113. 4
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 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,28

REFERENCES

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

LINKS

Table of n, a(n) for n=1..76.

FORMULA

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

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-Fran├žois Alcover, Aug 17 2019 *)

CROSSREFS

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

Sequence in context: A178638 A340786 A290496 * A146969 A338804 A090270

Adjacent sequences:  A035112 A035113 A035114 * A035116 A035117 A035118

KEYWORD

nonn,nice

AUTHOR

N. J. A. Sloane

EXTENSIONS

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

STATUS

approved

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Last modified June 20 23:24 EDT 2021. Contains 345312 sequences. (Running on oeis4.)