16.5. Specify pairwise distinct natural numbers $p, q, r, p_{1}, q_{1}, r_{1}$, for which $p^{2}+q^{2}+r^{2}=p_{1}^{2}+q_{1}^{2}+r_{1}^{2}$ and $p^{4}+q^{4}+r^{4}=p_{1}^{4}+q_{1}^{4}+r_{1}^{4}$ (Ramanujan).

## 16.2. Infinite sequences
16.5. Let's use Ramanujan's identity $f_{2}=f_{4}=0$ from problem 32.23. Setting $a=1, b=2, c=3$ and $d=6$, we obtain the required set of numbers $11,6,5$ and $10,9,1$.