A186989 Number of subsets of {1, 2, ..., n} containing n and having <=5 pairwise coprime elements.

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

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: A368436 A366616 A186988 * A186990 A186991 A186992

Adjacent sequences: A186986 A186987 A186988 * A186990 A186991 A186992

Keyword

nonn

Author

Alois P. Heinz, Mar 03 2011

Status

approved