OFFSET
1,2
LINKS
Peter Kagey, Table of n, a(n) for n = 1..10000
EXAMPLE
For n = 4:
step size 1: 0 -> 1 -> 2 -> 3 -> 4 (four steps);
step size 2: 4 -> 2 -> 0 (two steps);
step size 3: 0 -> 3 (one step).
Because the walker cannot take four steps down, a(4) = 4 + 2 + 1 = 7.
CROSSREFS
KEYWORD
nonn
AUTHOR
Peter Kagey, Feb 18 2017
STATUS
approved