OFFSET
0,3
MAPLE
a := n -> local k; if n = 0 then 1 else add((n + k - 1)! / (k!*(n - k)!), k = 1..n) fi: seq(a(n), n = 0..19);
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Luschny, Mar 09 2024
STATUS
approved