login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

T(n,k)=Number of nXk zero-sum -1..1 arrays with rows and columns lexicographically nondecreasing
8

%I #5 Mar 31 2012 12:36:46

%S 1,2,2,2,7,2,3,21,21,3,3,56,181,56,3,4,130,1341,1341,130,4,4,281,8312,

%T 29363,8312,281,4,5,555,44300,537572,537572,44300,555,5,5,1034,207562,

%U 8249505,29859761,8249505,207562,1034,5,6,1827,872998,108479344

%N T(n,k)=Number of nXk zero-sum -1..1 arrays with rows and columns lexicographically nondecreasing

%C Table starts

%C .1....2........2............3................3..................4

%C .2....7.......21...........56..............130................281

%C .2...21......181.........1341.............8312..............44300

%C .3...56.....1341........29363...........537572............8249505

%C .3..130.....8312.......537572.........29859761.........1387552127

%C .4..281....44300......8249505.......1387552127.......197324899476

%C .4..555...207562....108479344......54711391946.....23770010642604

%C .5.1034...872998...1248911674....1867753201968...2467219447235558

%C .5.1827..3348194..12812139620...56202066220732.224555987749683857

%C .6.3090.11857834.118772002152.1512619583145180

%H R. H. Hardin, <a href="/A202033/b202033.txt">Table of n, a(n) for n = 1..112</a>

%e Some solutions for n=2 k=7

%e .-1..0..0..0..0..1..1...-1.-1.-1..0..1..1..1...-1.-1..0..0..0..0..1

%e ..0.-1.-1.-1..0..1..1....0..0..1..0.-1..0..0....0..1.-1..0..0..0..1

%K nonn,tabl

%O 1,2

%A _R. H. Hardin_ Dec 09 2011