OFFSET
0,3
EXAMPLE
a(5) = 9 subsets: {}, {2}, {4}, {2, 3}, {2, 5}, {3, 4}, {2, 3, 5}, {2, 4, 5} and {3, 4, 5}.
CROSSREFS
KEYWORD
nonn
AUTHOR
Ilya Gutkovskiy, Jan 22 2024
EXTENSIONS
a(22)-a(35) from Alois P. Heinz, Jan 22 2024
STATUS
approved