OFFSET
1,2
COMMENTS
A permutation of the positive integers.
LINKS
FORMULA
Let r=sqrt(3) and s=r/(r-1). The tree-array T(n,k) is then
given by rows: T(0,0)=1; T(1,0)=2;
T(n,2j)=Floor(r*T(n-1),j));
T(n,2j+1)=Floor((s*T(n-1,j));
for j=0,1,...,2^(n-1)-1, n>=2.
EXAMPLE
First levels of the tree:
.....................1
.....................2
..............3..............4
..........5.......7......6.......9
........8..11..12..16..10..14..15..21
MATHEMATICA
a = {1, 2}; row = {a[[-1]]}; r = Sqrt[3]; s = r/(r - 1); Do[a = Join[a, row = Flatten[{Floor[#*{r, s}]} & /@ row]], {n, 5}]; a (* Ivan Neretin, Nov 09 2015 *)
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Clark Kimberling, Dec 23 2010
STATUS
approved