OFFSET
1,1
COMMENTS
If n==0 mod 5 a(n) < 0
PROG
(PARI) for(n=1, 20, print1(matdet(matrix(n, n, i, j, i^j+j^i)), ", "))
CROSSREFS
KEYWORD
easy,sign
AUTHOR
Benoit Cloitre, May 28 2002
STATUS
approved