Triangular-lattice strip conjecture for the 3p ± 1 widths

Let $q_0(L)$ denote the relevant real crossing for a triangular-lattice strip of width $L$ with fully periodic boundary conditions. Triangular-lattice 3p ± 1 conjecture. For all widths $L=3p\pm1$ with $p\geq1$, one has $q_0(L)=4$. The claim is inferred from exact values at several widths, including $2,4,5,7,8,10,11$, and is not resolved in the source.