%I A064764
%S A064764 1,2,3,4,6,6,12,12,12,12,18,18,24,24,24,24,35,35,44,44,44,44,55,55,55,
               55,
%T A064764 55,55,68,68,85,85,85,85,85,85,102,102,102,102,119,119,145,145,145,145,
%U A064764 174,174,174,174,174,174,203,203,203,203,203,203,232,232,261,261,261
%N A064764 Largest integer m such that every permutation (p_1, ..., p_n) of (1, 
               ..., n) satisfies lcm(p_i, p_{i+1}) >= m for some i, 1 <= i <= n-1.
%C A064764 For n >= 4, a(n) >= A073818(pi(n)), with equality for 19 <= n <= 70. 
               - David Wasserman (dwasserm(AT)earthlink.net), Aug 17 2002
%D A064764 P. Erdos, R. Freud and N. Hegyvari, Arithmetical properties of permutations 
               of integers, Acta Math. Hungar. 41 (1983), no. 1-2, 169-176.
%H A064764 D. Wasserman, <a href="http://home.earthlink.net/~dwasserm/A064764.html">
               Proof of terms 11-70</a>
%F A064764 a(n) = (1+o(1))n^2/(4 log n) as n -> infinity.
%e A064764 n=6: we must arrange the numbers 1..6 so that the max of the lcm of pairs 
               of adjacent terms is minimized. The answer is 632415, with max lcm 
               = 6, so a(6) = 6.
%Y A064764 Cf. A035106, A064796-A064797, A000720, A073818.
%Y A064764 Sequence in context: A064778 A028335 A007464 this_sequence A123131 A000793 
               A062163
%Y A064764 Adjacent sequences: A064761 A064762 A064763 this_sequence A064765 A064766 
               A064767
%K A064764 nonn,nice
%O A064764 1,2
%A A064764 N. J. A. Sloane (njas(AT)research.att.com), Oct 21 2001
%E A064764 More terms from Vladeta Jovovic (vladeta(AT)eunet.rs), Oct 21 2001
%E A064764 Further terms from David Wasserman (dwasserm(AT)earthlink.net), Aug 17 
               2002