OFFSET
0,4
PROG
(PARI) {a(n) = if( n<1, n>=0, (b(n+3) * b(n-1) * a(n-1)^2 - 1) / b(n+2))}
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Michael Somos, Sep 20 2001
STATUS
approved