Fix typo in arith-k-presum.md for k-th order prefix sums

weilycoder · weilycoder · commit bb68d899cea3 · 2025-04-30T20:25:45.000+08:00
diff --git a/source/_posts/arith-k-presum.md b/source/_posts/arith-k-presum.md
@@ -87,5 +87,5 @@ $$
 因此：
 
 $$
-a_n^{(k+1)}=[x^{n-1}]G_I^{k+1}(x)=\dbinom{n+k}{n-1}
+a_n^{(k)}=[x^{n-1}]G_I^{k+1}(x)=\dbinom{n+k}{n-1}
 $$
