The OEIS mourns the passing of Jim Simons and is grateful to the Simons Foundation for its support of research in many branches of science, including the OEIS.
login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A186499 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) before g(j) when f(i)=g(j), where f(i)=i^2 and g(j)=-4+5j^2. Complement of A186500. 6

%I #10 Mar 30 2012 18:57:19

%S 1,3,4,5,7,8,10,11,13,14,15,17,18,20,21,23,24,26,27,28,30,31,33,34,36,

%T 37,39,40,41,43,44,46,47,49,50,52,53,55,56,57,59,60,62,63,65,66,68,69,

%U 70,72,73,75,76,78,79,81,82,83,85,86,88,89,91,92,94,95,96,98,99,101,102,104,105,107,108,109,111,112,114,115,117,118,120,121,123,124,125,127,128,130,131,133,134,136,137,138,140,141,143,144

%N Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) before g(j) when f(i)=g(j), where f(i)=i^2 and g(j)=-4+5j^2. Complement of A186500.

%C See A186219 for a discussion of adjusted joint rank sequences.

%C The pairs (i,j) for which i^2=-4+5j^2 are (L(2h-2),F(2h-1)), where L=A000032 (Lucas numbers) and F=A000045 (Fibonacci numbers); compare this with the comment at A186511.

%F a(n)=n+floor((1/10)(sqrt(2n^2+7)))=A186499(n).

%F b(n)=n+floor(sqrt(5n^2-7/2))=A186500(n).

%e First, write

%e 1..4..9..16..25..36..49..... (i^2)

%e 1........16........41........(-4+5j^2)

%e Then replace each number by its rank, where ties are settled by ranking i^2 before -4+5j^2:

%e a=(1,3,4,5,7,8,10,11,13,14,15,17,18...)=A186499

%e b=(2,6,9,12,16,19,22,25,29,32,35,38,..)=A186500.

%t (* adjusted joint rank sequences a and b, using general formula for ranking ui^2+vi+w and xj^2+yj+z *)

%t d=1/2; u=1; v=0; w=0; x=5; y=0; z=4;

%t h[n_]:=-y+(4x(u*n^2+v*n+w-z-d)+y^2)^(1/2);

%t a[n_]:=n+Floor[h[n]/(2 x)];

%t k[n_]:=-v+(4u(x*n^2+y*n+z-w+d)+v^2)^(1/2);

%t b[n_]:=n + Floor[k[n]/(2 u)];

%t Table[a[n], {n, 1, 100}] (* A186499 *)

%t Table[b[n], {n, 1, 100}] (* A186500 *)

%Y Cf. A186219, A186500, A186511, A186512.

%K nonn

%O 1,2

%A _Clark Kimberling_, Feb 22 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified May 12 17:17 EDT 2024. Contains 372492 sequences. (Running on oeis4.)