A186159 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 triangular numbers and octagonal numbers. Complement of A186274.
1, 3, 4, 6, 7, 8, 10, 11, 13, 14, 16, 17, 18, 20, 21, 23, 24, 25, 27, 28, 30, 31, 32, 34, 35, 37, 38, 39, 41, 42, 44, 45, 47, 48, 49, 51, 52, 54, 55, 56, 58, 59, 61, 62, 63, 65, 66, 68, 69, 70, 72, 73, 75, 76, 77, 79, 80, 82, 83, 85, 86, 87, 89, 90, 92, 93, 94, 96, 97, 99, 100, 101, 103, 104, 106, 107, 108, 110, 111, 113, 114, 116, 117, 118, 120, 121, 123, 124, 125, 127, 128, 130, 131, 132, 134, 135, 137, 138, 139, 141
Offset: 1
Keywords
Examples
First, write the triangular and octagonal numbers: 1..3..6.....10..15..21..28 1........8..........21...... Then replace each by its rank, where ties are settled by ranking the triangular number before the octagonal: a=(1,3,4,6,7,8,10,11,13,...)=A186159. b=(2,5,9,12,15,19,22,26,...)=A186274.
Crossrefs
Programs
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Mathematica
(* adjusted joint ranking; general formula *) d=1/2; u=1/2; v=1/2; w=0; x=3; y=-2; z=0; h[n_]:=-y+(4x(u*n^2+v*n+w-z-d)+y^2)^(1/2); a[n_]:=n+Floor[h[n]/(2x)]; k[n_]:=-v+(4u(x*n^2+y*n+z-w+d)+v^2)^(1/2); b[n_]:=n+Floor[k[n]/(2u)]; Table[a[n],{n,1,100}] (* A186159 *) Table[b[n],{n,1,100}] (* A186274 *)
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