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A264799
Tree T generated by these rules: 0 is in T, and if x is in T, then x+1 and -2x are in T, with duplicates deleted as they occur.
2
0, 1, -2, 2, -4, -1, 3, 4, -8, -6, -3, 5, 8, -16, -10, -7, -5, 6, 9, 12, 16, -32, -24, -18, -15, -12, -9, 7, 10, 13, 14, 17, 20, 32, -64, -40, -34, -31, -28, -26, -23, -20, -17, -14, -11, 11, 15, 18, 21, 24, 30, 33, 36, 48, 64, -128, -96, -72, -66, -63, -60
OFFSET
0,3
COMMENTS
Every integer occur in T exactly once, so that this is a permutation of the integers. Let g(0) = {0}, g(1) = {1}, g(2) = {-2,2}, g(3) = {-4,-1,3,4}, etc. The number |g(n)| of numbers in the n-th generation is a Fibonacci number except for g(3); see A264800.
LINKS
EXAMPLE
Generations begin with
0
1
-2 2
-4 -1 3 4
-8 -6 -3 5 8
-16 -10 -7 -5 6 9 12 16
MATHEMATICA
z = 10; t = Expand[NestList[DeleteDuplicates[Flatten[Map[{# + 1, -2*#} &, #], 1]] &, {0}, z]]; s[0] = t[[1]]; s[n_] := s[n] = Union[t[[n]], s[n - 1]];
g[n_] := Complement[s[n], s[n - 1]]; g[1] = {0};
Table[Length[g[k]], {k, 1, z}] (* A264800 *)
u = Table[g[k], {k, 1, z}]
Flatten[u] (* A264799 *)
CROSSREFS
KEYWORD
sign,tabf,easy
AUTHOR
Clark Kimberling, Nov 25 2015
STATUS
approved