OFFSET
0,4
FORMULA
T(n, k) = s(k)*s(n-k) where s(n) = A056040(n).
EXAMPLE
1;
1, 1;
2, 1, 2;
6, 2, 2, 6;
6, 6, 4, 6, 6;
30, 6, 12, 12, 6, 30;
20, 30, 12, 36, 12, 30, 20;
140, 20, 60, 36, 36, 60, 20, 140;
70, 140, 40, 180, 36, 180, 40, 140, 70;
630, 70, 280, 120, 180, 180, 120, 280, 70, 630;
MAPLE
T := (n, k) -> k!*(n-k)!/(iquo(k, 2)!*iquo(n-k, 2)!)^2:
seq(seq(T(n, k), k=0..n), n=0..10);
CROSSREFS
KEYWORD
tabl,nonn
AUTHOR
Peter Luschny, Oct 01 2019
STATUS
approved