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.

A186288 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 pentagonal numbers. Complement of A186289.

Original entry on oeis.org

1, 3, 5, 7, 9, 11, 12, 14, 16, 18, 20, 21, 23, 25, 27, 29, 31, 32, 34, 36, 38, 40, 41, 43, 45, 47, 49, 51, 52, 54, 56, 58, 60, 61, 63, 65, 67, 69, 71, 72, 74, 76, 78, 80, 81, 83, 85, 87, 89, 90, 92, 94, 96, 98, 100, 101, 103, 105, 107, 109, 110, 112, 114, 116, 118, 120, 121, 123, 125, 127, 129, 130, 132, 134, 136, 138, 140, 141, 143, 145, 147, 149, 150, 152, 154, 156, 158, 160, 161, 163, 165, 167, 169, 170, 172, 174, 176, 178, 179, 181
Offset: 1

Views

Author

Clark Kimberling, Feb 17 2011

Keywords

Comments

See A186219 for a discussion of adjusted rank sequences.

Examples

			First, write
1..4...9....16....25..36..49..... (squares)
1....5...12....22....35......51.. (pentagonal)
Replace each number by its rank, where ties are settled by ranking the square number before the pentagonal:
a=(1,3,5,7,9,11,12,14,....)=A186288.
b=(2,4,6,8,10,13,15,17,...)=A186289.
		

Crossrefs

Cf. A186219, A186289, A186290, A186291, A000290 (squares), A000326 (pentagonal).

Programs

  • Mathematica
    (* adjusted joint ranking; general formula *)
    d=1/2; u=1; v=0; w=0; x=3/2; y=-1/2; 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}]  (* A186288 *)
    Table[b[n],{n,1,100}]  (* A186289 *)