OFFSET
1,2
COMMENTS
A permutation of the positive integers.
LINKS
FORMULA
Let L(n)=floor(r*n) and U(n)=floor(s*n), where r=4-sqrt(6) 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) = L(T(n-1),j); T(n,2j+1) = U(T(n-1),j);
for j=0,1,...,2^(n-1)-1, n>=2.
EXAMPLE
The top five rows:
1
2
3 5
4 8 7 14
6 11 12 22 10 19 21 39
MATHEMATICA
a = {1, 2}; row = {a[[-1]]}; r = 4 - Sqrt[6]; 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
AUTHOR
Clark Kimberling, Dec 23 2010
STATUS
approved