OFFSET
0,4
MAPLE
h:= l-> (n-> {{seq(seq(1+l[i]-j+add(`if`(l[k]<j, 0, 1),
k=i+1..n), j=1..l[i]), i=1..n)}})(nops(l)):
g:= (n, i, l)-> `if`(n=0 or i=1, h([l[], 1$n]),
{g(n, i-1, l)[], g(n-i, min(n-i, i), [l[], i])[]}):
a:= n-> nops(g(n$2, [])):
seq(a(n), n=0..30);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Mar 22 2018
STATUS
approved