[seqfan] help needed with former sequence A138036
N. J. A. Sloane
njas at research.att.com
Sun Sep 4 11:19:37 CEST 2011
Dear Seqfans, I admit I don't speak Mathematica.
Here is the definition of the former sequence A138036
(now deleted from the OEIS, but you can read the History):
Clear[a]; a = With[{n = 8, k = 3}, NestList[DeleteCases[Flatten[Map[Table[Append[ #, i - 1], {i, k}] &, # ], 1], {___, u__, v__} /; Sort[{u}] == Sort[{v}]] &, {{}}, n]]; Flatten[a]
which apparently produces
{{}},
{{0}, {1}, {2}},
{{0, 1}, {0, 2}, {1, 0}, {1, 2}, {2, 0}, {2, 1}},
{{0, 1, 0}, {0, 1, 2}, {0, 2, 0}, {0, 2, 1}, {1, 0, 1}, {1, 0, 2}, {1, 2, 0}, {1, 2, 1}, {2, 0, 1}, {2, 0, 2}, {2, 1, 0}, {2, 1, 2}},
{{0, 1,0, 2}, {0, 1, 2, 0}, {0, 1, 2, 1}, {0, 2, 0, 1}, {0, 2, 1, 0}, {0, 2, 1, 2}, {1, 0, 1, 2}, {1, 0, 2, 0}, {1, 0, 2, 1}, {1, 2, 0, 1}, {1, 2, 0, 2}, {1, 2, 1, 0}, {2, 0, 1, 0}, {2, 0, 1, 2}, {2, 0, 2, 1}, {2, 1, 0, 1}, {2, 1, 0, 2}, {2, 1, 2, 0}},
{{0, 1, 0, 2, 0}, {0, 1, 0, 2, 1}, {0, 1, 2, 0, 1}, {0, 1, 2, 0, 2}, {0, 1, 2, 1, 0}, {0, 2, 0,1, 0}, {0, 2, 0, 1, 2}, {0, 2, 1, 0, 1}, {0, 2, 1, 0,2}, {0, 2, 1, 2, 0}, {1, 0,1, 2, 0}, {1, 0, 1, 2, 1}, {1, 0, 2, 0, 1}, {1, 0, 2, 1, 0}, {1, 0, 2, 1, 2}, {1, 2, 0, 1, 0}, {1, 2, 0, 1, 2}, {1, 2, 0, 2, 1}, {1, 2, 1, 0, 1}, {1, 2, 1, 0, 2}, {2, 0,1, 0, 2}, {2, 0, 1, 2, 0}, {2, 0, 1, 2, 1}, {2, 0, 2,1, 0}, {2, 0, 2, 1, 2}, {2,1, 0, 1, 2}, {2, 1, 0, 2, 0}, {2, 1, 0, 2, 1}, {2, 1, 2, 0, 1}, {2, 1, 2, 0, 2}},
...
which then became the sequence
0, 1, 2, 0, 1, 0, 2, 1, 0, 1, 2, 2, 0, 2, 1, 0, 1, 0, 0, 1, 2, 0, 2, 0, 0, 2, 1, 1, 0, 1, 1, 0, 2, 1, 2, 0, 1, 2, 1, 2, 0, 1, 2, 0, 2, 2, 1, 0, 2, 1, 2, 0, 1, 0, 2, 0, 1, 2, 0, 0, 1, 2, 1, 0, 2, 0, 1, 0, 2, 1, 0, 0, 2, 1, 2, 1, 0, 1, 2, 1, 0, 2, 0, 1, 0, 2, 1, 1, 2, 0, 1, 1, 2, 0, 2, 1, 2, 1, 0, 2, 0, 1, 0, 2, 0, ...
which was A138036
which was recently deleted by the editors.
But the sequence looks interesting. Can anyone supply a definition
in English for it? Or is it indeed not worthy of being included?
Thanks
Neil
More information about the SeqFan
mailing list