This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A068063 #16 Feb 16 2025 08:32:45
%S A068063 0,1,1,2,2,2,2,3,3,3,4,4,4,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,6,6,6,
%T A068063 6,6,6,6,6,6,6,6,6,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,8
%N A068063 Maximum cardinality of a nondividing subset of {1, 2, ..., n}.
%C A068063 A set is called nondividing if no element divides the sum of any nonempty subset of the other elements.
%H A068063 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/NondividingSet.html">Nondividing Set</a>.
%e A068063 a(65) = 8 because 8 is the maximal cardinality of a nondividing subset of {1, 2, ..., 65}. Two different subsets have cardinality 8:
%e A068063 {36,40,48,49,53,61,64,65}, {30,44,45,49,50,59,64,65}.
%Y A068063 Cf. A051014, A187489.
%K A068063 more,nonn
%O A068063 0,4
%A A068063 _David Wasserman_, Feb 15 2002
%E A068063 a(41)-a(65) from _Alois P. Heinz_, Mar 10 2011