OFFSET
11,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 11..200
EXAMPLE
a(12) = 6 because there are 6 6-element subsets of {1, 2, ..., 12} having pairwise coprime elements: {1,2,3,5,7,11}, {1,5,7,8,9,11}, {1,4,5,7,9,11}, {1,3,5,7,8,11}, {1,3,4,5,7,11}, {1,2,5,7,9,11}.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Mar 02 2011
STATUS
approved