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.

A276760 Decimal expansion of the imaginary part of the fixed point of -exp(z) in C congruent with the branch K=1 of log(z)+2*Pi*K*i.

Original entry on oeis.org

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

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Author

Stanislav Sykora, Nov 12 2016

Keywords

Comments

Imaginary part of the complex constant z_2 whose real part is in A276759 (see the latter entry for more information).

Examples

			4.375185153061898385470906564852584291623823114677011864961044...
		

Crossrefs

Fixed points of -exp(z): z_0: A030178, and z_2: A276759 (real part), A276761 (modulus).
Fixed points of +exp(z): z_1: A059526, A059527, A238274, and z_3: A277681, A277682, A277683.

Programs

  • Mathematica
    RealDigits[Im[-ProductLog[-1, 1]], 10, 105][[1]] (* Jean-François Alcover, Nov 12 2016 *)
  • PARI
    default(realprecision,2050);eps=5.0*10^(default(realprecision))
    M(z,K)=log(-z)+2*Pi*K*I; \\ the convergent mapping (any K)
    K=1;z=1+I;zlast=z;
    while(1,z=M(z,K);if(abs(z-zlast)
    				

Formula

Let z_2 = A276759+i*A276760. Then z_2 = -exp(z_2) = log(-z_2)+2*Pi*i = -W_-1(1).