A146205 - OEIS

%I #2 Jun 01 2010 03:00:00

%S 35,35,245,245,735,735,1225,1225,1225,1225,735,735,245,245,35,35

%N Number of paths of the simple random walk on condition that the median applied to the partial sums S_0=0, S_1,...,S_n, n odd (n=15 in this example), is equal to half-integer values k+1/2, -[n/2]-1<=k<=[n/2].

%C 1) Closed-form expressions for sequences see Pfeifer (2010).

%C 2) The median taken on partial sums of the simple random walk represents the market price in a simulation model wherein a single security among non-cooperating and asymetrically informed traders is traded (Pfeifer et al. 2009).

%C 3) A146207=A146205+(0,A146206) see lemma 2 in Pfeifer (2010).

%D Pfeifer, C. (2010) Probability distribution of the median taken on partial sums of the simple random walk, Submitted to Stochastic Analysis and Applications

%H C. Pfeifer, K. Schredelseker, G. U. H. Seeber, <a href="http://dx.doi.org/10.1016/j.ejor.2008.01.015">On the negative value of information in informationally inefficient markets. Calculations for large number of traders</a>, Eur. J. Operat. Res., 195 (1) (2009) 117-126.

%e All possible different paths (sequences of partial sums) in case of n=3:

%e {0,-1,-2,-3}; median=-1.5

%e {0,-1,-2,-1}; median=-1

%e {0,-1,0,-1}; median=-0.5

%e {0,-1,0,1}; median=0

%e {0,1,0,-1}; median=0

%e {0,1,0,1}; median=0.5

%e {0,1,2,1}; median=1

%e {0,1,2,3}; median=1.5

%e sequence of integers in case of n=3: 1,1,1,1

%Y A117692, A108347, A029460, A029466, A135553, A137272, A146206, A146207

%K fini,nonn

%O 0,1

%A Christian Pfeifer (christian.pfeifer(AT)uibk.ac.at), Oct 28 2008, May 04 2010