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A084846 mu(n!+1), where mu is the Moebius function (A008683). 3
-1, -1, -1, -1, 0, 0, 1, 0, 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, -1, 1, 1, -1, -1, -1, 1, -1, -1, -1, 1, 1, -1, -1, 1, 1, 1, 1, 1, 1, -1, 1, 1, 1, 1, -1, -1, -1, 1, -1, 1, -1, 1, -1, 1, -1, -1, 1, 1, -1, -1, 1, -1, 1, -1, -1, -1, -1, -1, -1, 1, -1, 1, -1, 1, 1, 1, -1, 1, -1, 1, 1, -1, -1, 1, -1, 1, 1, 1, -1, 1, 1, 1, 1, 1, 1, -1, 1 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

COMMENTS

A064237 is the sequence of n such that a(n!+1) = 0.

LINKS

Table of n, a(n) for n=0..114.

Paul Leyland, Factors of n!+1.

Markus Tervooren et al., Factorization of n!+1, FactorDB.

EXAMPLE

a(6)=1 because 6!+1 = 721 = 7 * 103, the product of two different primes and

thus mu(6!+1) = (-1)^2 = 1.

PROG

(MAGMA) [MoebiusMu(Factorial(n)+1) : n in [1..45]];

(PARI) for(n=0, 45, print1(moebius(n!+1), ", "))

CROSSREFS

Cf. A008683 (mu(n)), A054990 (bigomega(n!+1)), A066856 (omega(n!+1)), A064237 (n!+1 divisible by a square), A002981 (n!+1 is prime).

Sequence in context: A302203 A130657 A185916 * A285498 A285504 A130093

Adjacent sequences:  A084843 A084844 A084845 * A084847 A084848 A084849

KEYWORD

hard,sign

AUTHOR

Rick L. Shepherd, Jun 10 2003

EXTENSIONS

a(112) corrected, a(113)-a(114) added by Max Alekseyev, May 28 2015

STATUS

approved

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Last modified June 18 18:52 EDT 2019. Contains 324215 sequences. (Running on oeis4.)