OFFSET
1,1
COMMENTS
A184928: 1, 5, 6, 11, 14, 18, 21, 23, 27, ...
A184929: 2, 6, 10, 13, 17, 20, 24, 28, 32, ...
A184930: 3, 7, 12, 16, 22, 25, 29, 34, 39, ...
A184931: 4, 9, 15, 19, 26, 31, 36, 41, 47, ...
Jointly rank the sets {h*r}, {i*s}, {j*t}, {k*u}, where h>=1, i>=1, j>=1, k>=1. The position of n*s in the joint ranking is n + [rn/s] + [tn/s] + [un/s], and likewise for the positions of n*r, n*t, and n*u.
MATHEMATICA
r=Sin[Pi/2]; s=Sin[Pi/3]; t=Sin[Pi/4]; u=Sin[Pi/5];
a[n_]:=n+Floor[n*s/r]+Floor[n*t/r]+Floor[n*u/r];
b[n_]:=n+Floor[n*r/s]+Floor[n*t/s]+Floor[n*u/s];
c[n_]:=n+Floor[n*r/t]+Floor[n*s/t]+Floor[n*u/t];
d[n_]:=n+Floor[n*r/u]+Floor[n*s/u]+Floor[n*t/u];
Table[a[n], {n, 1, 120}] (* A184928 *)
Table[b[n], {n, 1, 120}] (* A184929 *)
Table[c[n], {n, 1, 120}] (* A184930 *)
Table[d[n], {n, 1, 120}] (* A184931 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
Clark Kimberling, Jan 26 2011
STATUS
approved