diff --git a/constants/3a.md b/constants/3a.md
index f9a3102..f70f262 100644
--- a/constants/3a.md
+++ b/constants/3a.md
@@ -22,6 +22,7 @@ $$ |A-B| \gg |A+B|^{C_{3a}}.$$
 | $1.1479$ | [GGSWT2025] | AlphaEvolve
 | $1.173050$ |[G2025] |
 | $1.173077$ |[Z2025]|
+| $1.1740744$ | [SG2026] | Base-$21$ digit construction with exact counting certificate. |
 
 
 ## Additional comments and links
@@ -36,3 +37,4 @@ $C_{3a} \geq 1 + \log( \lvert U-U \rvert /\lvert U+U \rvert )/\log(2 \max(U)+1)$
 - [G2025] Gerbicz, Robert. Sums and differences of sets (improvement over AlphaEvolve), 2025. [arXiv:2505.16105](https://arxiv.org/abs/2505.16105).
 - [GHR2007] Gyarmati, Katalin; Hennecart, François; Ruzsa, Imre Z. Sums and differences of finite sets. Functiones et Approximatio Commentarii Mathematici, 37(1):175–186, 2007.
 - [Z2025] Zheng, Fan. Sums and differences of sets: a further improvement over AlphaEvolve, 2025. [arXiv:2506.01896](https://arxiv.org/abs/2506.01896).
+- [SG2026] Griego, Sebastian. Base-$21$ digit construction certificate for $C_{3a}$, submitted to this repository (2026).