OFFSET
1
COMMENTS
FORMULA
T(1,1)=T(2,2)=1; T(1,2)=T(2,1)=-1; T(n,k)=0 for all other (n,k).
a(n) = (1-(-1)^(2^abs((n*(n-1)*(n-2)*(n-3)*(n-5)))))/2*(-1)^((2*n-1+(-1)^n)/4). - Luce ETIENNE, Jul 09 2015
a(n) = (-1)^floor(n/2)*sign(floor(5/n))-floor(n/4)*floor(4/n). - Wesley Ivan Hurt, Jul 10 2015
EXAMPLE
Northwest corner:
.1....-1....0....0....0....0....0
-1.....1....0....0....0....0....0
.0.....0....0....0....0....0....0
.0.....0....0....0....0....0....0
MAPLE
A185906:=n->(-1)^floor(n/2)*signum(floor(5/n))-floor(n/4)*floor(4/n): seq(A185906(n), n=1..300); # Wesley Ivan Hurt, Jul 10 2015
CROSSREFS
KEYWORD
tabl,sign
AUTHOR
Clark Kimberling, Feb 06 2011
STATUS
approved