OFFSET
0,4
COMMENTS
FORMULA
G.f.: ( 1-x(1+y)-sqrt(1-2x(1+y)+x^2(1+y)(y-3)) )/(2x^2(1+y));
G.f.: 1/(1-x-xy-x^2(1+y)/(1-x-xy-x^2(1+y)/(1-... (continued fraction).
EXAMPLE
Triangle begins
1,
1, 1,
2, 3, 1,
4, 9, 6, 1,
9, 26, 26, 10, 1,
21, 75, 100, 60, 15, 1,
51, 216, 360, 295, 120, 21, 1,
127, 623, 1246, 1295, 735, 217, 28, 1,
323, 1800, 4200, 5292, 3864, 1624, 364, 36, 1
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Paul Barry, Dec 15 2010
STATUS
approved