[seqfan] Re: Kaku-Stroke-Bus route

[zbi74583.boat at orange.zero.jp]

    Hi,Giovanni

    Thanks so much for telling me the contradiction between A131709 and A135442.
    The reason why I haven't known it is the following.

    I have a little knowledge about graph theory and Max Alexeyev is an expert
so I believed in his result.
    He computed these terms.

    It is  not good that I haven't confirmed them.

    So  I computed again the first few term.

    A131709 : 1,4,14,...

    Fig for n=2
    ._._.   a b c
    |_|_|   x y z

    Graph   Name of vertice

    Stroke :
    ._._.
    |_|_|   yxabyzcb and symmetry       2

    ._._.
    |_|_|   yxabczyb and symmetry       4

    ._._.
    |_._|   abczyxa
      +
      |     by       and symmetry       4

    ._.
    |_.     baxy
      +
      ._.
      |_|   bczyb    an symmetry        4

    a(2)=2*4*4*4=14


    Notice that Bus route is undirected path.

    I think the number which  Max computed is not
correct.
    The first formula is mine.
    Could you confirm it?

    If the second formula is right then
    a(n)    : 1,4,34,....

    We must ask him about it.



    Yasutoshi