A124897 a(n) = mu(n^2 + 1), mu = A008683.

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

Offset: 1

Author

Reinhard Zumkeller, Nov 12 2006

Keywords

• sign

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A002522, A008683, A059592, A124895.

Programs

Mathematica

MoebiusMu[Range[107]^2+1] (* T. D. Noe, Nov 27 2006 *)

PARI

a(n) = moebius(n^2+1); \\ Michel Marcus, Jul 26 2022

Formula

a(n) = A008683(A002522(n)) = A124895(n,1);

a(n) = 0 iff A059592(n) > 1;

Extensions

Corrected by T. D. Noe, Nov 27 2006