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.

A186315 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 squares and hexagonal numbers. Complement of A186316.

Original entry on oeis.org

1, 3, 5, 7, 8, 10, 12, 13, 15, 17, 19, 20, 22, 24, 25, 27, 29, 30, 32, 34, 36, 37, 39, 41, 42, 44, 46, 48, 49, 51, 53, 54, 56, 58, 59, 61, 63, 65, 66, 68, 70, 71, 73, 75, 77, 78, 80, 82, 83, 85, 87, 89, 90, 92, 94, 95, 97, 99, 100, 102, 104, 106, 107, 109, 111, 112, 114, 116, 118, 119, 121, 123, 124, 126, 128, 129, 131, 133, 135, 136, 138, 140, 141, 143, 145, 147, 148, 150, 152, 153, 155, 157, 159, 160, 162, 164, 165, 167, 169, 170
Offset: 1

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Author

Clark Kimberling, Feb 17 2011

Keywords

Comments

See A186219 for a discussion of adjusted joint rank sequences.

Examples

			First, write
1..4...9...16..25....36....49. (squares)
1....6...15.......28....45.... (hexagonal)
Replace each number by its rank, where ties are settled by ranking the square number before the hexagonal:
a=(1,3,5,7,8,10,12,13,...)=A186315.
b=(2,4,6,9,11,14,16,18,...)=A186316.
		

Crossrefs

A000290 (squares), A000384 (hexagonal numbers).

Programs

  • Mathematica
    (* adjusted joint ranking; general formula *)
    d=1/2; u=1; v=0; w=0; x=2; y=-1; 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}]  (* A186315 *)
    Table[b[n], {n, 1, 100}]  (* A186316 *)