A186986 - OEIS

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A186986

Number of 10-element subsets of {1, 2, ..., n} having pairwise coprime elements.

8, 8, 16, 16, 24, 24, 268, 268, 1569, 1857, 1952, 2010, 2156, 2176, 9265, 9596, 10167, 10339, 35489, 35589, 103267, 107303, 111153, 115675, 297827, 301611, 442057, 451649, 484539, 503173, 1150127, 1164141, 1290703, 1320491, 1413885, 1471627

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OFFSET

23,1

LINKS

Alois P. Heinz, Table of n, a(n) for n = 23..200

EXAMPLE

a(24) = 8 because there are 8 10-element subsets of {1, 2, ..., 24} having pairwise coprime elements: {1,2,3,5,7,11,13,17,19,23}, {1,2,5,7,9,11,13,17,19,23}, {1,3,4,5,7,11,13,17,19,23}, {1,3,5,7,8,11,13,17,19,23}, {1,3,5,7,11,13,16,17,19,23}, {1,4,5,7,9,11,13,17,19,23}, {1,5,7,8,9,11,13,17,19,23}, {1,5,7,9,11,13,16,17,19,23}.

CROSSREFS

Column 10 of triangle A186974. Partial sums of A186981.

Sequence in context: A205709 A028997 A168397 * A112439 A309461 A245420

Adjacent sequences: A186983 A186984 A186985 * A186987 A186988 A186989

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Mar 02 2011

STATUS

approved