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A186989 Number of subsets of {1, 2, ..., n} containing n and having <=5 pairwise coprime elements. 4
1, 2, 4, 4, 12, 4, 28, 16, 32, 12, 110, 16, 209, 46, 69, 98, 507, 57, 828, 141, 277, 193, 1591, 163, 1289, 413, 1101, 441, 3785, 163, 5164, 1479, 1736, 1187, 2540, 609, 9561, 1879, 3086, 1304, 14298, 738, 18084, 3322, 3913, 3888, 25430 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Alois P. Heinz, Table of n, a(n) for n = 1..200

EXAMPLE

a(10) = 12 because there are 12 subsets of {1, 2, ..., 10} containing 10 and having <=5 pairwise coprime elements: {10}, {1,10}, {3,10}, {7,10}, {9,10}, {1,3,10}, {1,7,10}, {1,9,10}, {3,7,10}, {7,9,10}, {1,3,7,10}, {1,7,9,10}. There is no subset with exactly 5 elements here.

CROSSREFS

Column 5 of triangle A186975. Sum of A186988 and A186976.

Sequence in context: A263382 A286714 A186988 * A186990 A186991 A186992

Adjacent sequences:  A186986 A186987 A186988 * A186990 A186991 A186992

KEYWORD

nonn

AUTHOR

Alois P. Heinz, Mar 03 2011

STATUS

approved

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Last modified September 22 22:38 EDT 2021. Contains 347609 sequences. (Running on oeis4.)