A184923 a(n) = n+[r*n/u]+[s*n/u]+[t*n/u], where []=floor and r=2^(1/2), s=r+1, t=r+2, u=r+3.

1, 4, 6, 10, 11, 14, 17, 20, 21, 25, 28, 30, 34, 35, 38, 41, 44, 45, 49, 51, 54, 58, 59, 62, 65, 68, 69, 72, 75, 78, 79, 83, 86, 88, 92, 93, 96, 99, 102, 103, 107, 109, 112, 116, 117, 120, 123, 126, 127, 131, 133, 136, 137, 141, 144, 146, 150, 151, 154, 157, 160, 161, 165, 168, 170, 174, 175, 178, 181, 184, 185, 189, 191, 194, 198, 199, 202, 204, 208, 209, 212, 215, 218, 219, 223, 226, 228, 232, 233, 236, 239, 242, 243, 247, 249, 252, 256, 257, 260, 263, 266, 267, 270, 273, 276, 277, 281, 284, 286, 290, 291, 294, 297, 300, 301, 305, 307, 310, 314, 315

Offset: 1

Author

Clark Kimberling, Jan 26 2011

Keywords

• nonn

Comments

The sequences A184920-A184923 partition the positive integers:

A184920: 7,15,24,31,40,48,55,64,...

A184921: 3,8,13,18,23,27,32,37,...

A184922: 2,5,9,12,16,19,22,26,29,...

A184923: 1,4,6,10,11,14,17,20,21,...

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*u in the joint ranking is n+[r*n/u]+[s*n/u]+[t*n/u], and likewise for the positions of n*s, n*t, and n*u.

Crossrefs

Cf. A184912, A184920, A184921, A184922.

Programs

Mathematica

(* See A184920 *)