OFFSET
1,4
LINKS
FORMULA
The set: {k | k <= n, k == 1 (mod 3)} provides a lower bound: a(n) >= floor((n+2)/3).
EXAMPLE
The first few examples where a(n) increases are {1}, {1,4}, {1,4,6}, and {1,4,6,7}.
CROSSREFS
KEYWORD
nonn
AUTHOR
Zachary DeStefano, May 16 2023
STATUS
approved