A271523 Decimal expansion of the real part of the Dirichlet function eta(z), at z=i, the imaginary unit.

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

Offset: 0

Author

Stanislav Sykora, Apr 09 2016

Keywords

• nonn
• cons

Comments

The corresponding imaginary part of eta(i) is in A271524.

Examples

			0.53259318176309616657096500819731904472778576814349219223974872595...
		

Links

• Stanislav Sykora, Table of n, a(n) for n = 0..2000
• Eric Weisstein's World of Mathematics, Dirichlet Eta Function

Crossrefs

Cf. A002162 (eta(1)), A179311 (real(zeta(i))), A179836 (imag(-zeta(i))), A271524 (imag(eta(i))), A271525 (real(eta'(i))), A271526(-imag(eta'(i))).

Programs

Mathematica

First[RealDigits[Re[(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);
real(direta(I)) \\ Evaluation

Formula

Equals real(eta(i)).