This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A184921 #8 Jun 12 2025 08:35:58
%S A184921 3,8,13,18,23,27,32,37,42,47,52,56,61,66,71,76,81,85,90,95,100,105,
%T A184921 110,114,119,124,129,134,139,143,148,153,158,163,167,172,177,182,187,
%U A184921 192,196,201,206,211,216,221,225,230,235,240,245,250,254,259,264,269,274,279,283,288,293,298,303,308,312,317,322,327,332,336,341,346,351,356,361,365,370,375,380,385,390,394,399,404,409,414,419,423,428,433,438,443,448,452,457,462,467,472,477,481,486,491,496,501,505,510,515,520,525,530,534,539,544,549,554,559,563,568,573,578
%N A184921 a(n) = n+[r*n/s]+[t*n/s]+[u*n/s], where []=floor and r=2^(1/2), s=r+1, t=r+2, u=r+3.
%C A184921 The sequences A184920-A184923 partition the positive integers:
%C A184921 A184920: 7,15,24,31,40,48,55,64,...
%C A184921 A184921: 3,8,13,18,23,27,32,37,...
%C A184921 A184922: 2,5,9,12,16,19,22,26,29,...
%C A184921 A184923: 1,4,6,10,11,14,17,20,21,...
%C A184921 Jointly rank the sets {h*r}, {i*s}, {j*t}, {k*u}, where h>=1, i>=1, j>=1, k>=1.
%C A184921 The position of n*s in the joint ranking is n+[r*n/s]+[t*n/s]+[u*n/s], and likewise for the positions of n*r, n*t, and n*u.
%t A184921 (* See A184920 *)
%Y A184921 Cf. A184912, A184920, A184922, A184923.
%K A184921 nonn
%O A184921 1,1
%A A184921 _Clark Kimberling_, Jan 26 2011