The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 Hints (Greetings from The On-Line Encyclopedia of Integer Sequences!)
 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

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

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