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.

A186539 Adjusted joint rank sequence of (f(i)) and (g(j)) with f(i) before g(j) when f(i)=g(j), where f(i)=i^2 and g(j)=-2+3j^2. Complement of A186540.

Original entry on oeis.org

1, 3, 4, 6, 7, 9, 11, 12, 14, 15, 17, 18, 20, 22, 23, 25, 26, 28, 29, 31, 33, 34, 36, 37, 39, 41, 42, 44, 45, 47, 48, 50, 52, 53, 55, 56, 58, 59, 61, 63, 64, 66, 67, 69, 70, 72, 74, 75, 77, 78, 80, 82, 83, 85, 86, 88, 89, 91, 93, 94, 96, 97, 99, 100, 102, 104, 105, 107, 108, 110, 111, 113, 115, 116, 118, 119, 121, 123, 124, 126, 127, 129, 130, 132, 134, 135, 137, 138, 140, 141, 143, 145, 146, 148, 149, 151, 153, 154, 156, 157
Offset: 1

Views

Author

Clark Kimberling, Feb 23 2011

Keywords

Comments

See A186219 for a discussion of adjusted joint rank sequences.
Differs from A059555 at n=97, 123, 194, 220, 246, ... - R. J. Mathar, May 18 2020

Examples

			First, write
1..4..9..16..25..36..49.... (i^2)
.......10....25.....46.. (-2+3j^2)
Then replace each number by its rank, where ties are settled by ranking i^2 before -2+3j^2:
a=(1,3,4,6,7,9,11,12,14,15,17,18,..)=A186539
b=(2,5,8,10,13,16,19,21,24,27,30...)=A186540.
		

Crossrefs

Programs

  • Mathematica
    (* adjusted joint rank sequences a and b, using general formula for ranking ui^2+vi+w and xj^2+yj+z *)
    d = 1/2; u = 1; v = 0; w = 0; x = 3; y = 0; z = -2;
    h[n_] := -y + (4 x (u*n^2 + v*n + w - z - d) + y^2)^(1/2);
    a[n_] := n + Floor[h[n]/(2 x)];
    k[n_] := -v + (4 u (x*n^2 + y*n + z - w + d) + v^2)^(1/2);
    b[n_] := n + Floor[k[n]/(2 u)];
    Table[a[n], {n, 1, 100}]  (* A186539 *)
    Table[b[n], {n, 1, 100}]  (* A186540 *)

Formula

a(n)=n+floor(sqrt((1/3)n^2+1/24))=A186539(n).
b(n)=n+floor(sqrt(3n^2-3/2))=A186540(n).

A059556 Beatty sequence for 1 + 1/gamma.

Original entry on oeis.org

2, 5, 8, 10, 13, 16, 19, 21, 24, 27, 30, 32, 35, 38, 40, 43, 46, 49, 51, 54, 57, 60, 62, 65, 68, 71, 73, 76, 79, 81, 84, 87, 90, 92, 95, 98, 101, 103, 106, 109, 112, 114, 117, 120, 122, 125, 128, 131, 133, 136, 139, 142, 144, 147, 150, 153, 155, 158, 161, 163, 166
Offset: 1

Views

Author

Mitch Harris, Jan 22 2001

Keywords

Comments

Differs from A054088 at indices 56, 71, 112, 127, 142, 168, 183 etc. - R. J. Mathar, Oct 05 2008
Let r = gamma (the Euler constant, 0.5772...). When {k*r, k >= 1} is jointly ranked with the positive integers, A059555(n) is the position of n and A059556(n) is the position of n*r. - Clark Kimberling, Oct 21 2014

Crossrefs

Beatty complement is A059555.

Programs

  • Mathematica
    t = N[Table[k*EulerGamma, {k, 1, 200}]]; u = Union[Range[200], t]
    Flatten[Table[Flatten[Position[u, n]], {n, 1, 100}]]  (* A059556 *)
    Flatten[Table[Flatten[Position[u, t[[n]]]], {n, 1, 100}]] (* A059555 *)
    (* Clark Kimberling, Oct 21 2014 *)
  • PARI
    { default(realprecision, 100); b=1 + 1/Euler; for (n = 1, 2000, write("b059556.txt", n, " ", floor(n*b)); ) } \\ Harry J. Smith, Jun 28 2009

A250253 First row of spectral array W(gamma+1).

Original entry on oeis.org

1, 2, 3, 5, 7, 13, 20, 35, 55, 95, 149, 259, 408, 707, 1115, 1931, 3045, 5276, 8321, 14416, 22737, 39391, 62128, 107634, 169762, 294105, 463867, 803628, 1267494, 2195877, 3463371, 6000134, 9463505, 16395094
Offset: 1

Views

Author

Colin Barker, Nov 15 2014

Keywords

Comments

Gamma is Euler's (or Euler-Mascheroni) constant.

Crossrefs

Cf. A001620 (Gamma), A059555 (Corresponding Beatty sequence), A250254, A250255.

Programs

  • PARI
    \\ Row i of the generalized Wythoff array W(h),
    \\   where h is an irrational number between 1 and 2,
    \\   and m is the number of terms in the vectors a and b.
    row(h, i, m) = {
      if(h<=1 || h>=2, print("Invalid value for h"); return);
      my(
        a=vector(m, n, floor(n*h)),
        b=vector(m, n, floor(n*h/(h-1))),
        w=[a[a[i]], b[a[i]]],
        j=3
      );
      while(1,
        if(j%2==1,
          if(w[j-1]<=#a, w=concat(w, a[w[j-1]]), return(w))
        ,
          if(w[j-2]<=#b, w=concat(w, b[w[j-2]]), return(w))
        );
        j++
      )
    }
    allocatemem(10^9)
    row(Euler+1, 1, 10^7)
Showing 1-3 of 3 results.