OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..200
MAPLE
a:= proc(n) option remember; `if`(n<3, [1, 5, 166][n+1],
((108*n^2-72*n+4)*a(n-1)-6*(n-1)*(3*n-5)*(27*n^2-48*n+10)*a(n-2)
+9*(n-1)*(n-2)*(3*n-1)*(3*n-7)*(3*n-5)*(3*n-8)*a(n-3))/8)
end:
seq(a(n), n=0..20);
MATHEMATICA
G[n_, k_] := G[n, k] = Module[{j, g}, Which[k > n, G[n, n], n == 0, 1, k < 1, 0, True, g = G[n - k, k]; For[j = k - 1, j >= 1, j--, g = g(n-j)/j + G[n - j, k]]; g]];
a[n_] := G[3n, 3];
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 22 2013
STATUS
approved