OFFSET
1,1
FORMULA
G.f.=tz(2+z)/(1-2tz-z^2-tz^2).
EXAMPLE
T(4,2)=9 because we have (1,3),(1',3),(1,3'),(1',3'),(3,1),(3',1),(3,1'),(3',1') and (2,2).
Triangle begins:
2;
1,4;
2,4,8;
1,9,12,16;
2,8,30,32,32;
MAPLE
G:=t*z*(2+z)/(1-2*t*z-z^2-t*z^2): Gser:=simplify(series(G, z=0, 14)): for n from 1 to 12 do P[n]:=sort(coeff(Gser, z^n)) od: for n from 1 to 12 do seq(coeff(P[n], t^k), k=1..n) od; # yields sequence in triangular form
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Emeric Deutsch, Apr 09 2005
STATUS
approved