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.

Previous Showing 11-13 of 13 results.

A360095 Decimal expansion of Sum_{p primes, p == 3 (mod 4)} log(p)/p^2.

Original entry on oeis.org

2, 1, 2, 4, 4, 4, 7, 6, 8, 9, 3, 1, 6, 6, 5, 0, 5, 7, 7, 0, 5, 0, 6, 7, 7, 9, 2, 6, 8, 2, 8, 2, 5, 2, 1, 4, 8, 7, 0, 3, 7, 3, 6, 9, 5, 8, 4, 3, 7, 6, 6, 6, 9, 7, 8, 1, 0, 4, 9, 7, 5, 3, 7, 1, 6, 7, 7, 0, 9, 5, 9, 7, 6, 0, 2, 0, 8, 1, 1, 5, 3, 5, 8, 9, 6, 1, 3, 7, 0, 5, 9, 6, 1, 4, 0, 7, 4, 3, 8, 3, 3, 7, 4, 4, 7, 3
Offset: 0

Views

Author

Vaclav Kotesovec, Jan 25 2023

Keywords

Examples

			0.212444768931665057705067792682825214870373695843766697810497537167709...
		

Crossrefs

Programs

  • Mathematica
    beta[s_]:= (1 - 1/2^s) * Zeta[s] / DirichletBeta[s]; Do[Print[N[-1/2*Sum[MoebiusMu[2*n + 1]/(2*n + 1) * D[Log[beta[(2*n + 1)*s]], s] /. s->2, {n, 0, m}], 120]], {m, 10, 100, 10}]

Formula

Equals A136271 - A360094 - log(2)/4.

A340617 Decimal expansion of Product_{p prime, p == 3 (mod 4)} (1 - 2/p^2).

Original entry on oeis.org

7, 2, 1, 0, 9, 7, 9, 7, 8, 2, 4, 0, 7, 5, 2, 4, 1, 5, 8, 3, 2, 4, 3, 1, 1, 7, 7, 5, 0, 3, 5, 0, 6, 4, 1, 9, 3, 3, 2, 3, 8, 0, 0, 9, 4, 8, 8, 2, 2, 7, 0, 9, 0, 4, 4, 8, 6, 4, 2, 7, 7, 4, 6, 9, 5, 1, 2, 7, 0, 9, 1, 2, 6, 0, 3, 6, 6, 0, 3, 9, 4, 7, 1, 7, 2, 0, 6, 5, 0, 1, 7, 3, 7, 9, 8, 4, 9, 3, 6, 2, 2, 8, 8, 7, 6, 5
Offset: 0

Views

Author

Vaclav Kotesovec, Jan 13 2021

Keywords

Examples

			0.7210979782407524158324311775035064193323800948822709044864277469512...
		

Crossrefs

Programs

  • Maple
    Digits := 150;
    with(NumberTheory);
    DirichletBeta := proc(s) (Zeta(0, s, 1/4) - Zeta(0, s, 3/4))/4^s; end proc;
    alfa := proc(s) DirichletBeta(s)*Zeta(s)/((1 + 1/2^s)*Zeta(2*s)); end proc;
    beta := proc(s) (1 - 1/2^s)*Zeta(s)/DirichletBeta(s); end proc;
    pzetamod43 := proc(s, terms) 1/2*Sum(Moebius(2*j + 1)*log(beta((2*j + 1)*s))/(2*j + 1), j = 0..terms); end proc;
    evalf(exp(-Sum(2^t*pzetamod43(2*t, 70)/t, t = 1..200)));
  • Mathematica
    S[m_, n_, s_] := (t = 1; sums = 0; difs = 1; While[Abs[difs] > 10^(-digits - 5) || difs == 0, difs = (MoebiusMu[t]/t) * Log[If[s*t == 1, DirichletL[m, n, s*t], Sum[Zeta[s*t, j/m]*DirichletCharacter[m, n, j]^t, {j, 1, m}]/m^(s*t)]]; sums = sums + difs; t++]; sums);
    P[m_, n_, s_] := 1/EulerPhi[m] * Sum[Conjugate[DirichletCharacter[m, r, n]] * S[m, r, s], {r, 1, EulerPhi[m]}] + Sum[If[GCD[p, m] > 1 && Mod[p, m] == n, 1/p^s, 0], {p, 1, m}];
    Z2[m_, n_, s_] := (w = 1; sumz = 0; difz = 1; While[Abs[difz] > 10^(-digits - 5), difz = 2^w * P[m, n, s*w]/w; sumz = sumz + difz; w++]; Exp[-sumz]);
    $MaxExtraPrecision = 1000; digits = 121; RealDigits[Chop[N[Z2[4, 3, 2], digits]], 10, digits-1][[1]]

Formula

Equals 2*A065474/A335963.

A086240 Decimal expansion of Sum_{k>=2} (p mod 4 - 2)/p^2 where p=prime(k).

Original entry on oeis.org

0, 9, 4, 6, 1, 9, 8, 9, 2, 8, 9, 2, 9, 5, 0, 1, 5, 7, 9, 4, 5, 1, 8, 6, 7, 9, 0, 1, 4, 9, 1, 7, 4, 8, 0, 9, 6, 0, 1, 8, 8, 0, 3, 4, 0, 2, 4, 9, 7, 2, 1, 3, 5, 7, 1, 4, 8, 5, 9, 6, 0, 8, 5, 7, 5, 9, 4, 3, 1, 3, 7, 3, 2, 7, 5, 6, 2, 5, 5, 8, 4, 1, 6, 3, 9, 0, 4, 4, 2, 9, 3, 4, 6, 4, 3, 8, 0, 7, 9, 9, 6, 4, 2, 0, 8, 7
Offset: 0

Views

Author

Eric W. Weisstein, Jul 13 2003

Keywords

Examples

			0.094619892892950157945186790149174809601880340249721357148596...
		

References

  • S. R. Finch, Mathematical Constants, Encyclopedia of Mathematics and its Applications, vol. 94, Cambridge University Press, pp. 94-98

Formula

Equals A085991 - A086032. - Vaclav Kotesovec, Jun 19 2020

Extensions

A missing digit inserted and more digits added by R. J. Mathar, Jul 28 2010
More digits from Vaclav Kotesovec, Jun 19 2020
Previous Showing 11-13 of 13 results.