Das et al.'s congruence conjecture for generalized overcubic partitions

Let $\bar a_c(n)$ denote the generalized overcubic partition function, with $c$ a positive integer. For all integers $n\geq 0$ and $i\geq 1$, the following congruences are conjectured:

$$\begin{aligned} \bar a_{3i+2}(9n+2)&\equiv 0 \pmod{6},\\ \bar a_{3i+2}(9n+5)&\equiv 0 \pmod{6},\\ \bar a_{3i+2}(9n+8)&\equiv 0 \pmod{6},\\ \bar a_{9i+5}(9n+3)&\equiv 0 \pmod{12},\\ \bar a_{9i+8}(9n+3)&\equiv 0 \pmod{12}. \end{aligned}$$

Das et al.'s conjecture. For all $n\geq 0$ and $i\geq 1$, these five congruences hold.

The paper states that it provides elementary proofs of the conjectures proposed by Das et al.; thus the conjecture is resolved by the source paper. The congruences are part of the study of generalized overcubic partitions and extend known congruence families for the function $\bar a_c(n)$.