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.

A186328 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) before g(j) when f(i)=g(j), where f and g are the pentagonal numbers and the hexagonal numbers. Complement of A186329.

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%I A186328 #6 Mar 30 2012 18:57:18
%S A186328 1,3,5,7,9,11,13,15,16,18,20,22,24,26,28,29,31,33,35,37,39,41,43,44,
%T A186328 46,48,50,52,54,56,57,59,61,63,65,67,69,71,72,74,76,78,80,82,84,85,87,
%U A186328 89,91,93,95,97,99,100,102,104,106,108,110,112,113,115,117,119,121,123,125,126,128,130,132,134,136,138,140,141,143,145,147,149,151,153,154,156,158,160,162,164,166,168,169,171,173,175,177,179,181,182,184,186
%N A186328 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) before g(j) when f(i)=g(j), where f and g are the pentagonal numbers and the hexagonal numbers.  Complement of A186329.
%C A186328 See A186219 for a discussion of adjusted joint rank sequences.
%e A186328 First, write
%e A186328 1..5...12....22.....35......  (pentagonal)
%e A186328 1....6....15....28.......45.. (hexagonal)
%e A186328 Then replace each number by its rank, where ties are settled by ranking the pentagonal number before the hexagonal:
%e A186328 a=(1,3,5,7,9,11,13,15,16,....)=A186328
%e A186328 b=(2,4,6,8,10,12,14,17,19,...)=A186329.
%t A186328 (* adjusted joint ranking; general formula *)
%t A186328 d=1/2; u=3/2; v=-1/2; w=0; x=2; y=-1; z=0;
%t A186328 h[n_]:=-y+(4x(u*n^2+v*n+w-z-d)+y^2)^(1/2);
%t A186328 a[n_]:=n+Floor[h[n]/(2x)];
%t A186328 k[n_]:=-v+(4u(x*n^2+y*n+z-w+d)+v^2)^(1/2);
%t A186328 b[n_]:=n+Floor[k[n]/(2u)];
%t A186328 Table[a[n], {n, 1, 100}]  (* A186328 *)
%t A186328 Table[b[n], {n, 1, 100}]  (* A186329 *)
%Y A186328 Cf. A186219, A186329, A186330, A186331,
%Y A186328 A000384 (pentagonal), A000384 (hexagonal).
%K A186328 nonn
%O A186328 1,2
%A A186328 _Clark Kimberling_, Feb 17 2011