Review question

# Can we find $F(1) + F(2) + F(3) + \dots + F(100)$? Add to your resource collection Remove from your resource collection Add notes to this resource View your notes for this resource

Ref: R5875

## Question

The function $F(k)$ is defined for positive integers by $F(1)=1$, $F(2)=1$, $F(3)=-1$ and by the identities $F(2k)=F(k), \qquad F(2k+1)=F(k)$ for $k \ge 2$. The sum $F(1) + F(2) + F(3) + \dots + F(100)$ equals

1. $-15$;

2. $28$;

3. $64$;

4. $81$.