login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

The number of orderings of the hypercube Q_n whose disorder number is equal to the disorder number of Q_n.
0

%I #9 Sep 11 2022 09:30:28

%S 2,8,48,2304,4024320

%N The number of orderings of the hypercube Q_n whose disorder number is equal to the disorder number of Q_n.

%C A proof of a closed form for this sequence will settle Question 3.3 of the preprint "The disorder number of a graph" (see links).

%H M. Dominus, <a href="https://math.stackexchange.com/questions/315544/anti-gray-codes-that-maximize-the-number-of-bits-that-change-at-each-step">"Anti-Gray" codes that maximize the number of bits that change at each step</a>, Mathematics Stack Exchange, 2013.

%H Sela Fried, <a href="https://arxiv.org/abs/2208.03788">The disorder number of a graph</a>, arXiv:2208.03788 [math.CO], 2022.

%e For n = 2, there are exactly two orderings that begin at 00, whose disorder is the disorder number of Q_2, namely, [00, 11, 01, 10] and [00, 11, 10, 01]. Since we can start at any vertex, we need to multiply their number by 2^2, yielding a(2) = 8.

%Y Cf. A271771.

%K nonn,more

%O 1,1

%A _Sela Fried_, Aug 20 2022