A068063 - OEIS

A068063

Maximum cardinality of a nondividing subset of {1, 2, ..., n}.

0, 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5, 5, 5, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 6, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 7, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8, 8

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OFFSET

0,4

COMMENTS

A set is called nondividing if no element divides the sum of any nonempty subset of the other elements.

LINKS

Christian Sievers, Table of n, a(n) for n = 0..100

Eric Weisstein's World of Mathematics, Nondividing Set.

EXAMPLE

a(65) = 8 because 8 is the maximal cardinality of a nondividing subset of {1, 2, ..., 65}. Two different subsets have cardinality 8:

{36,40,48,49,53,61,64,65}, {30,44,45,49,50,59,64,65}.

CROSSREFS