OFFSET
0,3
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..140
FORMULA
a(p) = 2 * a(p-1) for prime p.
MAPLE
b:= proc(n, s) option remember; uses numtheory; `if`(n=0, 1, b(n-1, s)+
add(b(n-1, select(x-> x<n, s union {j})), j=factorset(n) minus s))
end:
a:= n-> b(n, {}):
seq(a(n), n=0..42);
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Feb 25 2024
STATUS
approved