OFFSET
0,8
COMMENTS
T is the transpose of the array in A125778.
LINKS
Alois P. Heinz, Antidiagonals n = 0..140, flattened
EXAMPLE
Diagonals (beginning on row 0): {1}; {1,1}; {1,1,1}; {1,2,2,1};...
MAPLE
T:= proc(h, k) option remember;
`if`([h, k]=[0, 0], 1, `if`(h<0 or k<0, 0, T(h-1, k)+
`if`(3*k>2*h and 3*(k-1)<2*h, 0, T(h, k-1))))
end:
seq(seq(T(h, d-h), h=0..d), d=0..20); # Alois P. Heinz, Apr 04 2012
MATHEMATICA
T[h_, k_] := T[h, k] = If[{h, k} == {0, 0}, 1, If[h<0 || k<0, 0, T[h-1, k]+If[3*k > 2*h && 3*(k-1) < 2*h, 0, T[h, k-1]]]]; Table[Table[T[h, d-h], {h, 0, d}], {d, 0, 20}] // Flatten (* Jean-François Alcover, Mar 03 2014, after Alois P. Heinz *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling. Definition revised Dec 08 2006
STATUS
approved