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.

A186156 Rank of n^3 when {i^3: i>=1} and {2j^2: j>=1} are jointly ranked with i^3 before 2j^2 when i^3=2j^2. Complement of A186157.

Original entry on oeis.org

1, 3, 6, 9, 12, 16, 20, 23, 28, 32, 36, 41, 46, 51, 56, 61, 66, 71, 77, 83, 89, 94, 100, 107, 113, 119, 126, 132, 139, 146, 153, 159, 167, 174, 181, 188, 196, 203, 211, 218, 226, 234, 242, 250, 258, 266, 274, 283, 291, 299, 308, 317, 325, 334, 343, 352, 361, 370, 379, 388, 397, 407, 416, 426, 435, 445, 454, 464, 474, 484, 494, 503, 514, 524, 534, 544, 554, 565, 575, 585, 596, 607, 617, 628, 639, 649, 660, 671, 682
Offset: 1

Views

Author

Clark Kimberling, Feb 13 2011

Keywords

Comments

See A186145 for a discussion of adjusted joint rank sequences.

Examples

			Write separate rankings as
1....8.....27........64........125...
..2..8..18....32..50....72..98.....128...
Then replace each number by its rank, where ties are settled by ranking i^3 before 2j^2.
		

Crossrefs

Programs

  • Mathematica
    d=1/2; u=1; v=2; p=3; q=2;
    h[n_]:=((u*n^p-d)/v)^(1/q);
    a[n_]:=n+Floor[h[n]]; (* rank of u*n^p *)
    k[n_]:=((v*n^q+d)/u)^(1/p);
    b[n_]:=n+Floor[k[n]]; (* rank of v*n^q *)
    Table[a[n],{n,1,100}] (* A186156 *)
    Table[b[n],{n,1,100}] (* A186157 *)

Formula

a(n)=n+floor(((n^3-1/2)/2)^(1/2)), A186156.
b(n)=n+floor((2n^2+1/2)^(1/3)), A186157.