nim L to R (#89)

Author: CharlesLakes

content/maths/reference/equations.typ

@@ -9,3 +9,6 @@ $ cases(a x + b y = e, c x + d y = f) arrow.double x = (e d - b f)/(a d - b c),
 *Recurrences:* If $a_n = c_1 a_(n-1) + dots.c + c_k a_(n-k)$ and $r_1, dots, r_k$ are distinct roots of $x^k - c_1 x^(k-1) - dots.c - c_k$, then:
 $ a_n = d_1 r_1^n + dots.c + d_k r_k^n $
 Non-distinct root $r$ becomes polynomial factor, e.g. $a_n = (d_1 n + d_2) r^n$.
+
+*Grundy number for nim L to R:*
+$ f(x) = floor((x mod (L+R))/L) $