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.

A380547 Decimal expansion of the absolute value of the sum of the Dirichlet L-series A000035 at s=1/2.

Original entry on oeis.org

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

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Author

R. J. Mathar, Jan 26 2025

Keywords

Comments

Defined as L(s) = (1-2^(-s))*zeta(s) by analytic continuation of the Riemann zeta function.

Examples

			Sum_{n>=1} A000035(n)/sqrt(n) = -0.42772793269397822132111661913967125635373339294116...
		

Crossrefs

Cf. A111003 (s=2), A233091 (s=3), A300707 (s=4), A059750 (zeta(1/2)), A000035, A010503, A113024, A268682.

Programs

  • Mathematica
    RealDigits[(1/Sqrt[2]-1)*Zeta[1/2], 10, 120][[1]] (* Amiram Eldar, Jan 26 2025 *)
  • PARI
    (1/sqrt(2)-1)*zeta(1/2) \\ Amiram Eldar, Jan 26 2025

Formula

Equals A010503 * A113024 = Sum_{n>=1} (-1)^(n+1)/sqrt(2*n). - Amiram Eldar, Jan 26 2025