OFFSET
0,3
LINKS
FORMULA
a(n) = A198085(n) - n + 1. - Gus Wiseman, Jun 11 2018
EXAMPLE
The a(3) = 9 clutters:
{}
{{1,2}}
{{1,3}}
{{2,3}}
{{1,2,3}}
{{1,2},{1,3}}
{{1,2},{2,3}}
{{1,3},{2,3}}
{{1,2},{1,3},{2,3}}
CROSSREFS
KEYWORD
nonn
AUTHOR
Gus Wiseman, May 23 2018
STATUS
approved