Computational experiments in finite two generator Burnside groups of exponent five

Let $B_0(2,5)=\langle a_1,a_2 \rangle$ be the largest two generator Burnside group of exponent five. It has the order $5^{34}$. There is a power commutator presentation of $B_0(2,5)$. In this case every element of the group can be represented uniquely as $a_1^{\alpha_1}\cdot a_2^{\alpha_2}\cdot\ldots\cdot a_{34}^{\alpha_{34}}$, $\alpha_i \in \mathbb{Z}_5$, $i=1,2,\ldots,34$. Here $a_1$ and $a_2$ are generators of $B_0(2,5)$, commutators $a_3,\ldots,a_{34}$ are defined recursively by $a_1$ and $a_2$. We define $B_k=B_0(2,5)/\langle a_{k+1},\ldots,a_{34}\rangle$ as a quotient of $B_0(2,5)$, $|B_k|=5^k$. Let $\varphi $ be the homomorphism of $ B_k $ onto the group $ Q_k $ and $ N_k $ be the kernel of $\varphi $. We have done some computational experiments and now formulate a hypothesis about the diameter $D_{A_4}(B_k)$ of the $B_k$ relative to the symmetric generating set $A_4 = \{ a_1,a_1^{-1},a_2,a_2^{-1}\}$: $D_{A_4}(eN_k) = D_{A_4}(B_k)$ for all $2\leq k \leq 34$ where $|N_k| \sim|Q_k| \sim |B_k|^{{1}/{2}}$, $e$ is the identity of $B_k$ and $D_{A_4}(eN_k)$ is the diameter of the coset $eN_k$. Note that this hypothesis is correct for $k \leq 19$.