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A186983 Number of 7-element subsets of {1, 2, ..., n} having pairwise coprime elements. 3
6, 6, 6, 8, 64, 65, 284, 297, 324, 339, 1116, 1144, 1784, 1886, 2449, 2576, 6499, 6527, 14386, 16178, 17683, 18649, 21003, 21395, 42708, 44997, 48966, 50310, 93138, 93852, 163212, 170778, 178896, 187722, 310605, 315687, 408771, 419661, 453255 (list; graph; refs; listen; history; text; internal format)
OFFSET

13,1

LINKS

Alois P. Heinz, Table of n, a(n) for n = 13..200

EXAMPLE

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

CROSSREFS

Column 7 of triangle A186974. Partial sums of A186978.

Sequence in context: A332559 A179415 A179409 * A046264 A291989 A035019

Adjacent sequences:  A186980 A186981 A186982 * A186984 A186985 A186986

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Mar 02 2011

STATUS

approved

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Last modified September 17 19:06 EDT 2021. Contains 347489 sequences. (Running on oeis4.)