A187493 Number of 6-element nondividing subsets of {1, 2, ..., n}.

1, 3, 4, 7, 15, 27, 45, 55, 85, 133, 199, 262, 378, 534, 803, 999, 1319, 1742, 2309, 3007, 4020, 5166, 6565, 7950, 10380, 12882, 16533, 19664, 24099, 30912, 37550, 44092, 54465, 65117, 79616, 94144, 111780, 132592, 159228, 187506, 219949, 256514

Offset

31,2

Comments

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

Links

Table of n, a(n) for n=31..72.

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

Column 6 of triangle A187489. Cf. A068063.

Sequence in context: A219277 A024368 A329666 * A027020 A130755 A361635

Adjacent sequences: A187490 A187491 A187492 * A187494 A187495 A187496

Keyword

nonn

Author

Alois P. Heinz, Mar 10 2011

Status

approved