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.

Showing 1-3 of 3 results.

A186380 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) before g(j) when f(i)=g(j), where f(i)=4i and g(j)=j(j+1)/2 (triangular number). Complement of A186379.

Original entry on oeis.org

1, 2, 4, 6, 8, 11, 14, 17, 20, 23, 27, 31, 35, 40, 45, 50, 55, 60, 66, 72, 78, 85, 92, 99, 106, 113, 121, 129, 137, 146, 155, 164, 173, 182, 192, 202, 212, 223, 234, 245, 256, 267, 279, 291, 303, 316, 329, 342, 355, 368, 382, 396, 410, 425, 440, 455, 470, 485, 501, 517, 533, 550, 567, 584, 601, 618, 636, 654, 672, 691, 710, 729, 748, 767, 787, 807, 827, 848, 869, 890, 911, 932, 954, 976, 998, 1021, 1044
Offset: 1

Views

Author

Clark Kimberling, Feb 19 2011

Keywords

Comments

See A186379.

Examples

			First, write
.....4..8..12..16..20..24..28.. (4*i)
1..3..6..10..15.....21.....28.. (triangular)
Then replace each number by its rank, where ties are settled by ranking 4i before the triangular:
a=(3,5,7,9,10,12,13,15,16,..)=A186379
b=(1,2,4,6,8,11,14,17,20,...)=A186380.
		

Crossrefs

Programs

Formula

a(n)=n+floor(-1/2+sqrt(8n-3/4))=A186379(n).
b(n)=n+floor((n^2+n+1)/8)=A186380(n).

A186381 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) after g(j) when f(i)=g(j), where f(i)=4i and g(j)=j(j+1)/2 (triangular number). Complement of A186382.

Original entry on oeis.org

3, 5, 7, 9, 10, 12, 14, 15, 17, 18, 19, 21, 22, 24, 25, 26, 28, 29, 30, 32, 33, 34, 36, 37, 38, 39, 41, 42, 43, 45, 46, 47, 48, 50, 51, 52, 53, 54, 56, 57, 58, 59, 61, 62, 63, 64, 65, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 79, 80, 81, 82, 83, 84, 86, 87, 88
Offset: 1

Views

Author

Clark Kimberling, Feb 19 2011

Keywords

Examples

			First, write
.....4..8..12..16..20..24..28.. (4*i)
1..3..6..10..15.....21.....28.. (triangular)
Then replace each number by its rank, where ties are settled by ranking 4i after the triangular:
a=(3,5,7,9,10,12,14,15,17,..)=A186381
b=(1,2,4,6,8,11,13,16,20,...)=A186382.
		

Crossrefs

Programs

  • Mathematica
    (* adjusted joint rank sequences a and b, using general formula for ranking 1st degree u*n+v and 2nd degree x*n^2+y*n+z *)
    d=-1/2; u=4; v=0; x=1/2; y=1/2; (* 4i and triangular *)
    h[n_]:=(-y+(4x(u*n+v-d)+y^2)^(1/2))/(2x);
    a[n_]:=n+Floor[h[n]]; (* rank of u*n+v *)
    k[n_]:=(x*n^2+y*n-v+d)/u;
    b[n_]:=n+Floor[k[n]]; (* rank of x*n^2+y*n+d *)
    Table[a[n], {n, 1, 120}]  (* A186381 *)
    Table[b[n], {n, 1, 100}]  (* A186382 *)

A186382 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) after g(j) when f(i)=g(j), where f(i)=4i and g(j)=j(j+1)/2 (triangular number). Complement of A186381.

Original entry on oeis.org

1, 2, 4, 6, 8, 11, 13, 16, 20, 23, 27, 31, 35, 40, 44, 49, 55, 60, 66, 72, 78, 85, 91, 98, 106, 113, 121, 129, 137, 146, 154, 163, 173, 182, 192, 202, 212, 223, 233, 244, 256, 267, 279, 291, 303, 316, 328, 341, 355, 368, 382, 396, 410, 425, 439, 454, 470, 485, 501, 517, 533, 550, 566, 583, 601, 618, 636, 654, 672, 691, 709, 728, 748, 767, 787, 807, 827, 848, 868, 889, 911, 932, 954, 976, 998, 1021, 1043, 1066, 1090
Offset: 1

Views

Author

Clark Kimberling, Feb 19 2011

Keywords

Comments

See A186381.

Examples

			See A186381.
		

Crossrefs

Programs

Showing 1-3 of 3 results.