# Greetings from The On-Line Encyclopedia of Integer Sequences! http://oeis.org/ Search: id:a184915 Showing 1-1 of 1 %I A184915 #4 Mar 30 2012 18:57:17 %S A184915 1,5,8,12,15,18,22,25,27,31,35,38,41,45,48,51,54,57,61,65,67,71,75,77, %T A184915 80,84,87,91,94,97,100,104,107,110,114,117,121,124,126,130,134,136, %U A184915 140,144,147,150,153,156,160,162,166,170,173,176,179,182,186,189,192,196,200,201,205,209,212,216,219,222,226,229,231,235,239,242,245,249,252,255,258,261,265,269,271,275,278,281,284,288,291,295,298,301,304,308,310,314,317,321,325,327,330,334,337,340,344,347,351,354,356,360,364,366,370,374,377,379,383,386,390,393 %N A184915 n+[rn/u]+[sn/u]+[tn/u], where []=floor and r=2^(1/5), s=r^2, t=r^3, u=r^4. %C A184915 The sequences A184912-A184915 partition the positive integers: %C A184915 A184912: 4,9,13,19,23,28,34,... %C A184915 A184913: 3,7,11,16,20,24,30,... %C A184915 A184914: 2,6,10,14,17,21,26,... %C A184915 A184915: 1,5,8,12,15,18,22,... %C A184915 The joint ranking method of A184812 is extended here to four numbers r,s,t,u, as follows: jointly rank the sets {h*r}, {i*s}, {j*t}, {k*u}, h>=1, i>=1, j>=1, k>=1. %C A184915 The position of n*u in the joint ranking is %C A184915 n+[rn/u]+[sn/u]+[tn/u], and likewise for the %C A184915 positions of n*r, n*s, and n*t. %t A184915 r=2^(1/5); s=2^(2/5); t=2^(3/5); u=2^(4/5); %t A184915 a[n_]:=n+Floor[n*s/r]+Floor[n*t/r]+Floor[n*u/r]; %t A184915 b[n_]:=n+Floor[n*r/s]+Floor[n*t/s]+Floor[n*u/s]; %t A184915 c[n_]:=n+Floor[n*r/t]+Floor[n*s/t]+Floor[n*u/t]; %t A184915 d[n_]:=n+Floor[n*r/u]+Floor[n*s/u]+Floor[n*t/u]; %t A184915 Table[a[n],{n,1,120}] (* A184912 *) %t A184915 Table[b[n],{n,1,120}] (* A184913 *) %t A184915 Table[c[n],{n,1,120}] (* A184914 *) %t A184915 Table[d[n],{n,1,120}] (* A184915 *) %Y A184915 Cf. A184812, A184912, A184913, A184914. %K A184915 nonn %O A184915 1,2 %A A184915 _Clark Kimberling_, Jan 25 2011 # Content is available under The OEIS End-User License Agreement: http://oeis.org/LICENSE