Walter Shur

collaborators

2 papers

math.CO2013

The Last Digit of $(n 2 n)$ and $\sum (i n) (n - i 2 n - 2 i)$

Walter Shur

Let $f_{n} = \sum_{i = 0}^{n} (i n) (n - i 2 n - 2 i)$ , $g_{n} = \sum_{i = 1}^{n} (i n) (n - i 2 n - 2 i)$ . Let ${a_{k}}_{k = 1}$ be the set of all positive integers n, in increas…

math.CO2013

Even and Odd Pairs of Lattice Paths with Multiple Intersections

Ira M. Gessel, Walter Shur

Let M(n,k,r,s) be the number of ordered paths in the plane, with unit steps E or N, that intersect k times in which the first path ends at the point (r,n-r) and the second path end…

The Last Digit of (n2n​) and ∑(in​)(n−i2n−2i​)

Even and Odd Pairs of Lattice Paths with Multiple Intersections

The Last Digit of $(n 2 n)$ and $\sum (i n) (n - i 2 n - 2 i)$