diff --git a/the on-line encyclopedia of integer sequences.md b/the on-line encyclopedia of integer sequences.md
index c8758b3d2..59c971ead 100644
--- a/the on-line encyclopedia of integer sequences.md	
+++ b/the on-line encyclopedia of integer sequences.md	
@@ -4,3 +4,4 @@
     - [[mersenne numbers]] https://oeis.org/A000225
     - [[mersenne primes]] https://oeis.org/A001348
     - [[hex numbers]] https://oeis.org/search?q=1%2C7%2C19%2C37%2C61%2C91
+    - [[hexagonal numbers]] https://oeis.org/A000384