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 1-6 of 6 results.

A138054 Levels of substitution A059832 taken as polynomials p(x,n)]and coefficients of the differential polynomials returned as q(x,n) = dp(x,n)dx coefficients (first three zeros omitted).

Original entry on oeis.org

2, 6, 3, 2, 6, 12, 1, 4, 9, 8, 15, 6, 14, 24, 2, 6, 6, 12, 5, 12, 21, 24, 9, 20, 33, 24, 39, 14, 30, 48, 3, 2, 6, 12, 15, 6, 14, 24, 18, 30, 11, 24, 39, 14, 30, 48, 34, 54, 19, 40, 63, 66, 23, 48, 75, 52, 81, 28, 58, 90, 1, 4, 9, 8, 15, 6, 14, 24, 9, 20, 33, 24, 39, 14, 30, 48, 51, 18
Offset: 1

Views

Author

Roger L. Bagula and Gary W. Adamson, May 02 2008

Keywords

Comments

Row sums are (with zeros) {0, 0, 0, 8, 23, 81, 305, 1027, 3514, 12002, 40658, ...}.
This sequence is as a result of my Pc Mandelbrot-Julia work.
I noticed that these substitution levels increased like iteration polynomials, so I converted the substitution levels to polynomials.
To get a good implicit plot I have been using the inverse of the differential in polynomials as a product.
So I used that kind of procedure to get the differentiation of a substitution.

Examples

			Three zeros then:
{2, 6},
{3, 2, 6, 12},
{1, 4, 9, 8, 15, 6, 14, 24},
{2, 6, 6, 12, 5, 12, 21, 24, 9, 20, 33, 24, 39, 14, 30, 48},
		

Crossrefs

Programs

  • Mathematica
    Clear[a, s, p, t, m, n] (* substitution *) s[1] = {2}; s[2] = {3}; s[3] = {1, 2, 3}; t[a_] := Flatten[s /@ a]; p[0] = {1}; p[1] = t[p[0]]; p[n_] := t[p[n - 1]]; (*A059832*) a = Table[p[n], {n, 0, 10}]; Flatten[a]; b = Table[CoefficientList[D[Apply[Plus, Table[a[[n]][[m]]*x^( m - 1), {m, 1, Length[a[[n]]]}]], x], x], {n, 1, 11}]; Flatten[b] Table[Apply[Plus, CoefficientList[D[Apply[Plus, Table[a[[n]][[m]]* x^(m - 1), {m, 1, Length[a[[n]]]}]], x], x]], {n, 1, 11}];

Formula

p(x,n)=Sum[A059832[n,m]*t(m-1),{m,1,n}]; q(x,n)=dp(x,n)dx; out_n,m=Coefficients(q(x,n).

A305389 A ternary tribonacci sequence: define the morphism f: 1 -> 2, 2 -> 3, 3 -> 1,2,3; let S[k] be result of applying f k times to 1, for k =- 0,1,2,...; sequence gives limit S[3k] as k -> oo.

Original entry on oeis.org

1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3
Offset: 0

Views

Author

N. J. A. Sloane, Jun 21 2018

Keywords

Crossrefs

The three sequence A305389, A305390, A305391 together give the limiting forms of the rows of A059832.
See A316324, A316325, A316326 for indices of 1's, 2's, 3's respectively.

A305390 A ternary tribonacci sequence: define the morphism f: 1 -> 2, 2 -> 3, 3 -> 1,2,3; let S[k] be result of applying f k times to 1, for k =- 0,1,2,...; sequence gives limit S[3k+1] as k -> oo.

Original entry on oeis.org

2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3
Offset: 0

Views

Author

N. J. A. Sloane, Jun 21 2018

Keywords

Crossrefs

The three sequence A305389, A305390, A305391 together give the limiting forms of the rows of A059832.
Used by A107793.

A305391 A ternary tribonacci sequence: define the morphism f: 1 -> 2, 2 -> 3, 3 -> 1,2,3; let S[k] be result of applying f k times to 1, for k =- 0,1,2,...; sequence gives limit S[3k+2] as k -> oo.

Original entry on oeis.org

3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 2, 3, 1, 2, 3, 3, 1, 2, 3, 2, 3, 1, 2, 3, 1, 2
Offset: 0

Views

Author

N. J. A. Sloane, Jun 21 2018

Keywords

Crossrefs

The three sequence A305389, A305390, A305391 together give the limiting forms of the rows of A059832.

A107793 Differences between successive indices of 1's in the ternary tribonacci sequence A305390.

Original entry on oeis.org

4, 5, 3, 5, 4, 5, 4, 5, 3, 5, 4, 5, 5, 4, 5, 3, 5, 4, 5, 3, 5, 4, 5, 5, 4, 5, 3, 5, 4, 5, 4, 5, 3, 5, 4, 5, 5, 4, 5, 3, 5, 4, 5, 4, 5, 3, 5, 4, 5, 5, 4, 5, 3, 5, 4, 5, 3, 5, 4, 5, 5, 4, 5, 3, 5, 4, 5, 4, 5, 3, 5, 4, 5, 5, 4, 5, 3, 5, 4, 5, 5, 4, 5, 3, 5, 4, 5, 4, 5, 3, 5, 4, 5, 5, 4, 5, 3, 5, 4, 5
Offset: 0

Views

Author

Roger L. Bagula, Jun 11 2005

Keywords

Comments

Average value is 4.38095...
Conjecture (N. J. A. Sloane, Jun 22 2018) This is a disguised form of A275925. More precisely, if we replace the 5's by 6's and the 4's by 5's, and ignore the first two terms, we appear to get a sequence which is a shifted version of A275925.

Crossrefs

Programs

  • Maple
    # From N. J. A. Sloane, Jun 22 2018. The value 16 can be replaced (in two places) by any number congruent to 1 mod 3.
    with(ListTools); S := Array(0..30);
    psi:=proc(T) Flatten(subs( {1=[2], 2=[3], 3=[1,2,3]}, T)); end;
    S[0]:=[1];
    for n from 1 to 16 do S[n]:=psi(S[n-1]): od:
    # Get differences between indices of 1's in S:
    Bag:=proc(S) local i,a; global DIFF; a:=[];
    for i from 1 to nops(S) do if S[i]=1 then a:=[op(a),i]; fi; od:
    DIFF(a); end;
    Bag(S[16]);
  • Mathematica
    s[1] = {2}; s[2] = {3}; s[3] = {1, 2, 3}; t[a_] := Flatten[s /@ a]; p[0] = {1}; p[1] = t[p[0]]; p[n_] := t[p[n - 1]] pp = p[13] a = Flatten[Table[If[pp[[j]] == 1, j, {}], {j, 1, Length[pp]}]] b = Table[a[[n]] - a[[n - 1]], {n, 2, Length[a]}]

Extensions

Edited (and checked) by N. J. A. Sloane, Jun 21 2018 (the original version did not make it clear that this is based on only one of the three tribonacci sequences A305389, A305390, A305391).

A059835 Form triangle as follows: start with three single digits: 0, 1, 2. Each succeeding row is a concatenation of the previous three rows.

Original entry on oeis.org

0, 1, 2, 0, 1, 2, 1, 2, 0, 1, 2, 2, 0, 1, 2, 1, 2, 0, 1, 2, 0, 1, 2, 1, 2, 0, 1, 2, 2, 0, 1, 2, 1, 2, 0, 1, 2, 1, 2, 0, 1, 2, 2, 0, 1, 2, 1, 2, 0, 1, 2, 0, 1, 2, 1, 2, 0, 1, 2, 2, 0, 1, 2, 1, 2, 0, 1, 2, 2, 0, 1, 2, 1, 2, 0, 1, 2, 0, 1, 2, 1, 2, 0, 1, 2, 2, 0, 1, 2, 1, 2, 0, 1, 2, 1, 2, 0, 1, 2, 2, 0, 1, 2, 1, 2
Offset: 0

Views

Author

Jason Earls, Feb 25 2001

Keywords

Comments

Trajectory of 0 under the morphism 0 -> 1, 1-> 2, 2 -> 012. - Robert G. Wilson v, May 20 2014
The sequence of row lengths is A000213. - Michael Somos, May 22 2014

Examples

			Triangle begins:
  0
  1
  2
  0 1 2
  1 2 0 1 2
  2 0 1 2 1 2 0 1 2
  ...
		

References

  • C. Pickover, Wonders of Numbers, Oxford University Press, NY, 2001, p. 273.

Crossrefs

Cf. A059832.

Programs

  • Maple
    T:= proc(n) option remember;
          `if`(n<3, n, seq(T(i), i=n-3..n-1))
        end:
    seq(T(n), n=0..10);  # Alois P. Heinz, May 22 2014
  • Mathematica
    NestList[ Flatten[# /. {0 -> {1}, 1 -> {2}, 2 -> {0, 1, 2}}] &, {0}, 8] // Flatten (* Robert G. Wilson v, May 20 2014 *)

Formula

a(n) = A059832(n) - 1. - Sean A. Irvine, Oct 11 2022

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Feb 26 2001
Showing 1-6 of 6 results.