OFFSET
1,2
COMMENTS
Joint-rank arrays are introduced here as follows.
Suppose that R={f(i,j)} is set of positive numbers, where i and j range through countable sets I and J, respectively, such that for every n, then number f(i,j) < n is finite. Let T(i,j) be the position of f(i,j) in the joint ranking of all the numbers in R. The joint-rank array of R is the array T whose i-th row is T(i,j).
For A182801, f(i,j)=j*r^(i-1), where r=(1+sqrt(5))/2 and I=J={1,2,3,...}.
Every positive integer occurs exactly once in A182801, so that as a sequence it is a permutation of the positive integers.
FORMULA
T(i,j)=Sum{floor(j*r^(i-k)): k>=1}.
EXAMPLE
Northwest corner:
1....3....5....7...10...12...
2....6....9...13...18...21...
4...11...16...23...31...36...
8...19...28...39...52...61...
MATHEMATICA
r=GoldenRatio;
f[i_, j_]:=Sum[Floor[j*r^(i-k)], {k, 1, i+Log[r, j]}];
TableForm[Table[f[i, j], {i, 1, 16}, {j, 1, 16}]] (* A182801 *)
CROSSREFS
KEYWORD
nonn,tabl
AUTHOR
Clark Kimberling, Dec 04 2010
STATUS
approved