A141473 - OEIS

%I #18 Oct 01 2024 03:24:49

%S 6,2,2,0,0,4,2,0,0

%N Number of 3-equitable permutations: permutations on n letters equally avoiding each permutation of S_3.

%C A permutation is 3-equitable if no omega in S_3 appears more than ceiling(binomial(n,3)/6) times or fewer than floor(binomial(n,3)/6) times.

%C E.g., 2143 contains 214, 213--213 permutations--and 243 and 143--both 132 permutations.

%C This is a generalization of the Kendall-Mann numbers A000140.

%H Sunil Abraham, <a href="/A141473/a141473.txt">Maple program</a>

%e The only 3-equitable permutations in S_4: [3, 1, 4, 2], [2, 4, 1, 3].

%Y Cf. A000140.

%K nonn,hard,more

%O 3,1

%A Sunil Abraham (sunil.abraham(AT)lmh.ox.ac.uk), Aug 08 2008