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.

A271524 Decimal expansion of the imaginary part of the Dirichlet function eta(z), at z=i, the imaginary unit.

Original entry on oeis.org

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

Views

Author

Stanislav Sykora, Apr 09 2016

Keywords

Comments

The corresponding real part of eta(i) is in A271523.

Examples

			0.229384857728525892457886733558081938225195415266121034625072393...
		

Crossrefs

Cf. A002162 (eta(1)), A179311 (real(zeta(i))), A179836 (imag(-zeta(i))), A271523 (real(eta(i))), A271525 (real(eta'(i))), A271526(-imag(eta'(i))).

Programs

  • Mathematica
    First[RealDigits[Im[(1 - 2^(1 - I))*Zeta[I]], 10, 110]] (* Robert Price, Apr 09 2016 *)
  • PARI
    \\ The Dirichlet eta function (fails for z=1):
    direta(z)=(1-2^(1-z))*zeta(z);
    imag(direta(I))\\ Evaluation

Formula

Equals imag(eta(i)).