OFFSET
1,1
LINKS
G. C. Greubel, Table of n, a(n) for n = 1..1000
FORMULA
MATHEMATICA
Table[Which[PrimeQ[n], -1, SquareFreeQ[n], 0, True, 1], {n, 110}] (* Harvey P. Dale, Aug 30 2015 *)
PROG
(PARI) for(n=1, 105, print1(if(!issquarefree(n), 1, if(isprime(n), -1, 0)), ", "))
CROSSREFS
KEYWORD
sign
AUTHOR
Giovanni Teofilatto, May 16 2005
EXTENSIONS
Edited and extended by Klaus Brockhaus, May 16 2005
STATUS
approved