OFFSET
0,9
LINKS
R. K. Guy, Catwalks, sandsteps and Pascal pyramids, J. Integer Sequences, Vol. 3 (2000), Article #00.1.6
W. F. Klostermeyer, M. E. Mays, L. Soltes and G. Trapp, A Pascal rhombus, Fibonacci Quarterly, 35 (1997), 318-328.
FORMULA
a(n, k) = a(n-1, k-2)+a(n-1, k) with a(0, 0)=1 and a(n, k)=0 if k < 0 or k > n.
EXAMPLE
1;
1 0;
1 0 1;
1 0 2 0;
1 0 3 0 2;
1 0 4 0 5 0;
1 0 5 0 9 0 5;
...
CROSSREFS
KEYWORD
AUTHOR
N. J. A. Sloane, Jan 26 2000
EXTENSIONS
More terms from Henry Bottomley, Aug 23 2001
STATUS
approved