A conjecture of Radu and Sellers on congruences modulo powers of 2 for broken 3-diamond partitions

Abstract: In 2007, Andrews and Paule introduced the family of functions $\Delta_k(n)$, which enumerate the number of broken $k$-diamond partitions for a fixed positive integer $k$. In 2013, Radu and Sellers completely characterized the parity of $\Delta_3(8n + r)$ for some $r$ and gave a conjecture on congruences modulo powers of 2 for broken 3-diamond partitions. We use an unconventional $U$-sequence to solve the revised conjecture proposed by Radu and Sellers.