OFFSET
1,3
LINKS
EXAMPLE
a(1) = 1:
1
a(2) = 1:
2 -> 11
a(3) = 2:
3 -> 111
3 -> 21 -> 111
a(4) = 7:
4 -> 1111
4 -> 211 -> 1111
4 -> 31 -> 1111
4 -> 31 -> 211 -> 1111
4 -> 22 -> 1111
4 -> 22 -> 112 -> 1111
4 -> 22 -> 211 -> 1111
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Sep 22 2019
STATUS
approved