OFFSET
31,2
COMMENTS
A set is called nondividing if no element divides the sum of any nonempty subset of the other elements.
LINKS
Eric Weisstein's World of Mathematics, Nondividing Set
EXAMPLE
a(31) = 1 because there is one 6-element nondividing subset of {1,2,...,31}: {16,19,23,24,28,31}.
CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Mar 10 2011
STATUS
approved