OFFSET
1,2
COMMENTS
EXAMPLE
a(14) = 1*(1)*2*(-1)*7*(-1)*14*(1) = 14^2 = 196.
MAPLE
MATHEMATICA
a[n_] := Product[d MoebiusMu[n/d], {d, Divisors[n]}];
Array[a, 62] (* Jean-François Alcover, Jun 24 2019 *)
PROG
(PARI) a(n)={local(r=1); fordiv(n, d, r*=d*moebius(n/d)); return(r); }
CROSSREFS
KEYWORD
sign
AUTHOR
Peter Luschny, Jul 22 2011
STATUS
approved