OFFSET
0,3
COMMENTS
FORMULA
G.f. G=G(t, z) satisfies (1-t)z^4*G^4-(1-t)z^3*G^3+zG^2-G+1=0.
EXAMPLE
T(4,1)=4 because we have UDUUUDDD, UUUDDDUD, UUUDUDDD and UUUDDUDD, where U=(1,1), D=(1,-1).
Triangle starts:
1;
1;
2;
4,1;
10,4;
27,15;
79,50,3;
240,168,21;
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Emeric Deutsch, Dec 03 2005
STATUS
approved