cp's OEIS Frontend

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.

A186326 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) after g(j) when f(i)=g(j), where f and g are the squares and octagonal numbers. Complement of A186327.

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%I A186326 #8 Apr 20 2018 00:39:16
%S A186326 2,3,5,6,8,9,11,12,14,16,17,19,20,22,24,25,27,28,30,31,33,35,36,38,39,
%T A186326 41,42,44,46,47,49,50,52,53,55,57,58,60,61,63,65,66,68,69,71,72,74,76,
%U A186326 77,79,80,82,83,85,87,88,90,91,93,94,96,98,99,101,102,104,106,107,109,110,112,113,115,117,118,120,121,123,124,126,128,129,131,132,134,135,137,139,140,142,143,145,147,148,150,151,153,154,156,158
%N A186326 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) after g(j) when f(i)=g(j), where f and g are the squares and octagonal numbers.  Complement of A186327.
%H A186326 Matthias Christandl, Fulvio Gesmundo, Asger Kjærulff Jensen, <a href="https://arxiv.org/abs/1801.04852">Border rank is not multiplicative under the tensor product</a>, arXiv:1801.04852 [math.AG], 2018.
%e A186326 First, write
%e A186326 1..4...9..16....25..36....49..64...  (squares)
%e A186326 1....8.......21........40........65. (octagonal)
%e A186326 Replace each number by its rank, where ties are settled by ranking the square number after the octagonal:
%e A186326 a=(2,3,5,6,8,9,11,12,14,...)=A186326
%e A186326 b=(1,4,7,10,13,15,18,21,...)=A186327.
%t A186326 (* adjusted joint ranking; general formula *)
%t A186326 d=-1/2; u=1; v=0; w=0; x=3; y=-2; z=0;
%t A186326 h[n_]:=-y+(4x(u*n^2+v*n+w-z-d)+y^2)^(1/2);
%t A186326 a[n_]:=n+Floor[h[n]/(2x)];
%t A186326 k[n_]:=-v+(4u(x*n^2+y*n+z-w+d)+v^2)^(1/2);
%t A186326 b[n_]:=n+Floor[k[n]/(2u)];
%t A186326 Table[a[n], {n, 1, 100}]  (* A186326 *)
%t A186326 Table[b[n], {n, 1, 100}]  (* A186327 *)
%Y A186326 Cf. A186219, A186324, A186325, A186327.
%K A186326 nonn
%O A186326 1,1
%A A186326 _Clark Kimberling_, Feb 17 2011