cp's OEIS Frontend

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.

Showing 1-2 of 2 results.

A035188 Coefficients in expansion of Dirichlet series Product_p (1-(Kronecker(m,p)+1)*p^(-s)+Kronecker(m,p)*p^(-2s))^(-1) for m = 6.

Original entry on oeis.org

1, 1, 1, 1, 2, 1, 0, 1, 1, 2, 0, 1, 0, 0, 2, 1, 0, 1, 2, 2, 0, 0, 2, 1, 3, 0, 1, 0, 2, 2, 0, 1, 0, 0, 0, 1, 0, 2, 0, 2, 0, 0, 2, 0, 2, 2, 2, 1, 1, 3, 0, 0, 2, 1, 0, 0, 2, 2, 0, 2, 0, 0, 0, 1, 0, 0, 2, 0, 2, 0, 2, 1, 2, 0, 3, 2, 0, 0, 0, 2, 1
Offset: 1

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Author

N. J. A. Sloane

Keywords

Comments

Coefficients of Dedekind zeta function for the quadratic number field of discriminant 24. See A002324 for formula and Maple code. - N. J. A. Sloane, Mar 22 2022

Links

Crossrefs

Dedekind zeta functions for imaginary quadratic number fields of discriminants -3, -4, -7, -8, -11, -15, -19, -20 are A002324, A002654, A035182, A002325, A035179, A035175, A035171, A035170, respectively.
Dedekind zeta functions for real quadratic number fields of discriminants 5, 8, 12, 13, 17, 21, 24, 28, 29, 33, 37, 40 are A035187, A035185, A035194, A035195, A035199, A035203, A035188, A035210, A035211, A035215, A035219, A035192, respectively.
Cf. A038877, A097934.

Programs

  • Mathematica
    a[n_] := If[n < 0, 0, DivisorSum[n, KroneckerSymbol[6, #] &]]; Table[ a[n], {n, 1, 100}] (* G. C. Greubel, Apr 27 2018 *)
  • PARI
    my(m=6); direuler(p=2,101,1/(1-(kronecker(m,p)*(X-X^2))-X))
  • PARI
    a(n) = sumdiv(n, d, kronecker(6, d)); \\ Amiram Eldar, Nov 20 2023

Formula

From Amiram Eldar, Oct 17 2022: (Start)
a(n) = Sum_{d|n} Kronecker(6, d).
Asymptotic mean: Limit_{m->oo} (1/m) * Sum_{k=1..m} a(k) = log(5+2*sqrt(6)) / sqrt(6) = 0.935881... . (End)
Multiplicative with a(p^e) = 1 if Kronecker(6, p) = 0 (p = 2 or 3), a(p^e) = (1+(-1)^e)/2 if Kronecker(6, p) = -1 (p is in A038877), and a(p^e) = e+1 if Kronecker(6, p) = 1 (p is in A097934). - Amiram Eldar, Nov 20 2023

A097934 Primes p that divide 3^((p-1)/2) - 2^((p-1)/2).

Original entry on oeis.org

5, 19, 23, 29, 43, 47, 53, 67, 71, 73, 97, 101, 139, 149, 163, 167, 173, 191, 193, 197, 211, 239, 241, 263, 269, 283, 293, 307, 311, 313, 317, 331, 337, 359, 379, 383, 389, 409, 431, 433, 457, 461, 479, 499, 503, 509, 523, 547, 557, 571, 577, 599, 601, 619
Offset: 1

Views

Author

Cino Hilliard, Sep 04 2004

Keywords

Comments

Rational primes that decompose in the field Q(sqrt(6)). - N. J. A. Sloane, Dec 26 2017
All terms belong to A038876(n) = Primes p such that 6 is a square mod p. Only first two terms of A038876(n), 2 and 3, do not belong to a(n). - Alexander Adamchuk, May 04 2007
From Jianing Song, Oct 13 2022: (Start)
Primes p such that kronecker(6,p) = 1 (or equivalently, kronecker(24,p) = 1).
Primes congruent to 1, 5, 9, 23 modulo 24. (End)

Examples

			For p=5, 3^2 - 2^2 = 5.

Links

Crossrefs

Cf. A038876 (primes p such that 6 is a square mod p), A038877 (rational primes that remain inert in the field Q(sqrt(6))).

Programs

  • Mathematica
    okQ[n_]:=Module[{c=(n-1)/2},Divisible[3^c-2^c,n]]; Select[Prime[Range[200]],okQ]  (* Harvey P. Dale, Apr 13 2011 *)
  • PARI
    /* Set x=3,d=1,s=-1 */
ptopm1d2(n,x,d,s) = { forprime(p=3,n,p2=(p-1)/2; y=x^p2 + s*(x-d)^p2; if(y%p==0,print1(p", "))) }
  • PARI
    isA097934(p) == isprime(p) && kronecker(6,p) == 1 \\ Jianing Song, Oct 13 2022

Formula

a(n) = A038876(n+1). - Alexander Adamchuk, May 04 2007
Showing 1-2 of 2 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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