A099990 a(n) = Moebius(2n+1).

1, -1, -1, -1, 0, -1, -1, 1, -1, -1, 1, -1, 0, 0, -1, -1, 1, 1, -1, 1, -1, -1, 0, -1, 0, 1, -1, 1, 1, -1, -1, 0, 1, -1, 1, -1, -1, 0, 1, -1, 0, -1, 1, 1, -1, 1, 1, 1, -1, 0, -1, -1, -1, -1, -1, 1, -1, 1, 0, 1, 0, 1, 0, -1, 1, -1, 1, 0, -1, -1, 1, 1, 1, 0, -1, -1, 0, 1, -1, 1, 1, -1, -1, -1, 0, 0, -1, 0, 1, -1, -1, 1, 1, 1, 0, -1, -1, -1, -1, -1, 1, 1, 1, 0, 1

Offset: 0

Author

N. J. A. Sloane, Nov 20 2004

Keywords

• sign
• easy

Links

• Amiram Eldar, Table of n, a(n) for n = 0..10000
• J. W. Coltman, The Specification of Imaging Properties by Response to a Sine Wave Input, J. Opt. Soc. Am., JOSA 44, 468 (1954).
• R. L. Lucke, Deriving the Coltman Correction for Transforming the Bar Transfer Function to the Optical Transfer Function (or the Contrast Transfer Function to the Modulation Transfer Function), Appl. Opt. 37, 7248 (1998).

Crossrefs

Bisection of A008683.

Cf. A099991.

Programs

Mathematica

a[n_] := MoebiusMu[2*n + 1]; Array[a, 100, 0] (* Amiram Eldar, Jul 23 2023 *)

PARI

a(n) = moebius(2*n+1); \\ Michel Marcus, Aug 12 2021