A187494 Number of 7-element nondividing subsets of {1, 2, ..., n}.
1, 1, 3, 3, 5, 5, 9, 12, 21, 27, 41, 46, 74, 99, 137, 153, 203, 307, 414, 464, 612, 788, 1126, 1292, 1645, 2039, 2614, 3291, 4120, 5127, 6356, 7180, 9786
Offset: 43
Examples
a(43) = 1 because there is one 7-element nondividing subset of {1,2,...,43}: {24,28,31,35,36,40,43}.
Links
- Eric Weisstein's World of Mathematics, Nondividing Set
Comments