Four remaining 2-adic congruences for overpartition tuples with odd parts

From papers

Let OPTk(n)\overline{OPT}_k(n) denote the number of overpartition kk-tuples of nn with odd parts. The four-congruence conjecture. For all i1i\geq 1, n0n\geq 0, and odd r>0r>0,

OPT2ir(8n+2)0(mod22i+1),OPT2ir(8n+4)0(mod22i+4),OPT2ir(8n+6)0(mod22i+3),OPT2ir(8n+7)0(mod2i+4).\begin{aligned} \overline{OPT}_{2^i r}(8n+2)&\equiv 0 \pmod{2^{2i+1}},\\ \overline{OPT}_{2^i r}(8n+4)&\equiv 0 \pmod{2^{2i+4}},\\ \overline{OPT}_{2^i r}(8n+6)&\equiv 0 \pmod{2^{2i+3}},\\ \overline{OPT}_{2^i r}(8n+7)&\equiv 0 \pmod{2^{i+4}}. \end{aligned}

These are the four remaining congruences from a previously proposed set of seven; the source states that they have not been proved, so their general validity remains open.

Progress summary

Nothing recorded yet. Refresh searches the literature and the public web for attempts on this problem, and writes the first summary here.

Sources & referencesView supporting material

Primary source

G. Kavya Keerthana, S. Ananya and Ranganatha D, “Congruences modulo powers of 2 and 3 for overpartition k-tuples”, arXiv:2509.17705 (2025).

Solutions 0

No solutions have been posted yet.