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.

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A103682 Trajectory of 1 under repeated applications of the morphism 1-> {1,2}, 2->{1,2,3}, 3->{1,1,3}.

Original entry on oeis.org

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

Views

Author

Roger L. Bagula, Mar 26 2005

Keywords

Crossrefs

Cf. A073058.

Programs

  • Mathematica
    s[1] = {1, 2}; s[2] = {1, 2, 3}; s[3] = {1, 1, 3}; t[a_] := Join[a, Flatten[s /@ a]]; a = t[t[t[t[t[{1}]]]]]

A105056 Triangle read by rows, based on the morphism f: 1->2, 2->3, 3->4, 4->{4,4,7,5}, 5->6, 6->7, 7->8, 8->{8,8,3,1}. First row is 1. If current row is a,b,c,..., then the next row is a,b,c,...,f(a),f(b),f(c),...

Original entry on oeis.org

1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 4, 4, 7, 5, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 4, 4, 7, 5, 2, 3, 3, 4, 3, 4, 4, 4, 4, 7, 5, 3, 4, 4, 4, 4, 7, 5, 4, 4, 4, 7, 5, 4, 4, 7, 5, 4, 4, 7, 5, 4, 4, 7, 5, 8, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4
Offset: 0

Views

Author

Roger L. Bagula, Apr 04 2005

Keywords

Comments

This sequence is the next level of substitution suggested in section 6 of the Kenyon paper. A tile exists at this level as well.

Crossrefs

Programs

  • Mathematica
    s[n_] := n /. {1 -> 2, 2 -> 3, 3 -> 4, 4 -> {4, 4, 7, 5}, 5 -> 6, 6 -> 7, 7 -> 8, 8 -> {8, 8, 3, 1}}; t[a_] := Join[a, Flatten[s /@ a]]; Flatten[ NestList[t, {1}, 6]]

A105061 Triangle read by rows, based on the morphism f: 1->2, 2->3, 3->4, 4->5, 5->{5,5,9,6}, 6->7, 7->8, 8->9, 9->10, 10->{10,10,4,1}. First row is 1. If current row is a,b,c,..., then the next row is a,b,c,...,f(a),f(b),f(c),...

Original entry on oeis.org

1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 4, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 5, 5, 9, 6, 1, 2, 2, 3, 2, 3, 3, 4, 2, 3, 3, 4, 3, 4, 4, 5, 2, 3, 3, 4, 3, 4, 4, 5, 3, 4, 4, 5, 4, 5, 5, 5, 5, 9, 6, 2, 3, 3, 4
Offset: 1

Views

Author

Roger L. Bagula, Apr 05 2005

Keywords

Comments

Level five bi-Kenyon substitution sequence.

Crossrefs

Programs

  • Mathematica
    s[n_] := n /. {1 -> 2, 2 -> 3, 3 -> 4, 4 -> 5, 5 -> {5, 5, 9, 6}, 6 -> 7, 7 -> 8, 8 -> 9, 9 -> 10, 10 -> {10, 10, 4, 1}}; t[a_] := Join[a, Flatten[s /@ a]]; Flatten[ NestList[t, {1}, 6]]

A105256 Sign doubling substitution of the Rauzy: 1->{1,2},2->{1,3},3->1 using a digraphy symmetry to the bi-Kenyon version (not a triangular nest of nests, but a straight level 5).

Original entry on oeis.org

1, 4, 2, 4, 2, 1, 5, 1, 3, 4, 2, 1, 5, 1, 3, 1, 5, 1, 3, 4, 2, 4, 6, 4, 2, 1, 4, 2, 1, 5, 1, 3, 1, 5, 1, 3, 4, 2, 4, 6, 4, 2, 1, 1, 5, 1, 3, 4, 2, 4, 6, 4, 2, 1, 4, 2, 4, 6, 4, 2, 1, 1, 5, 1, 3, 1, 5, 4, 1, 5, 1, 3, 4, 2, 4, 2, 1, 5, 1, 3, 1, 5, 1, 3, 4, 2, 4, 6, 4, 2, 1, 1, 5, 1, 3, 4, 2, 4, 6, 4, 2, 1, 4, 2, 4
Offset: 0

Views

Author

Roger L. Bagula, Apr 14 2005

Keywords

Comments

The French/ Siegel Rauzy substitution is: 1->{1,2} 2->{1,3} 3->{1} This is digraph symmetrical to the Kenyon type substitution : 1->{2} 2->{3} 3->{3,2,1} Looking at the digraph of: 1->{2} 2->{3} 3->{6,2,1} 4->{5} 5->{6} 6->{3,5,4} I get the same linked two triangle structure for this six-symbol substitution. The problem with the digraph approach is that the order is not specific as it is in actual substitutions.

References

  • "The Construction of Self-Similar Tilings", Richard Kenyon, Section 6

Crossrefs

Programs

  • Mathematica
    s[1] = {4, 2}; s[2] = {1, 3}; s[3] = {1}; s[4] = {1, 5}; s[5] = {4, 6}; s[6] = {4}; t[a_] := Join[a, Flatten[s /@ a]]; p[0] = {1}; p[1] = t[{1}]; p[n_] := t[p[n - 1]] aa = p[5]

Formula

1->{4, 2} 2->{1, 3} 3->{1} 4->{1, 5} 5->{4, 6} 6->{4}

A105265 Concatenation of letters of words obtained from axiom "1" and the iterates of the substitutions '1' -> "12", '2' -> "3", '3' -> "4", '4' -> "1".

Original entry on oeis.org

1, 1, 2, 1, 2, 1, 2, 3, 1, 2, 1, 2, 3, 1, 2, 3, 1, 2, 3, 4, 1, 2, 1, 2, 3, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 1, 2, 1, 2, 3, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4, 1, 1, 2, 3, 4, 1, 2, 3, 4, 1, 1, 2, 3, 4
Offset: 0

Views

Author

Roger L. Bagula, Apr 15 2005

Keywords

Comments

Let W() be the substitution defined above. If we define the sequence S(n) by S(0) = {1}, S(n+1) = S(n) + W(S(n)), then this sequence is the limiting sequence of S(n) as n approaches infinity. - Charlie Neder, Jul 11 2018

Crossrefs

Cf. A073058.

Programs

  • Mathematica
    s[1] = {1, 2}; s[2] = {3}; s[3] = {4}; s[4] = {1};
    t[a_] := Join[a, Flatten[s /@ a]];
    p[0] = {1}; p[1] = t[{1}]; p[n_] := t[p[n - 1]]
    aa = p[6]

Extensions

New name from Joerg Arndt, Jul 14 2018

A248335 A recursive sequence generated by an L-system defined in comments.

Original entry on oeis.org

1, 23, 3445, 45565667, 5667677867787889, 6778788978898990788989908990901, 7889899089909018990901901112899090190111290111211223, 89909019011129011121122390111211223112232323349011121122311223232334112232323342323343445
Offset: 1

Views

Author

Felix Fröhlich, Oct 26 2014

Keywords

Comments

The L-system producing the sequence is defined as follows:
Alphabet: 1 2 3 4 5 6 7 8 9 0
Initiator: 1
Production rules: (1 --> 23), (2 --> 34), (3 --> 45), (4 --> 56), (5 --> 67), (6 --> 78), (7 --> 89), (8 --> 90), (9 --> 1), (0 --> 12).

Crossrefs

A103956 A nonsense sequence.

Original entry on oeis.org

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

Views

Author

Roger L. Bagula, Mar 30 2005

Keywords

Crossrefs

Programs

  • Mathematica
    Conway[1] = Conway[2] = 1;
    Conway[n_Integer?Positive] := Conway[n] = Conway[Conway[n - 1]] + Conway[n - Conway[n - 1]]
    s[1] = {1, 2}; s[2] = {1, 3}; s[3] = {1};
    t[a_] := Join[a, Flatten[s /@ a]];
    p[0] = {1}; p[1] = t[{1}];
    p[n_] := t[p[n - 1]]
    aa = Flatten[Table[p[If[n > 0, Conway[n], n]], {n, 0, 7}]]

Formula

1-> {1, 2} 2->{1, 3} 3->1 nested nest of substitution list are taken in a chaotic order.

A103957 A nonsense sequence.

Original entry on oeis.org

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

Views

Author

Roger L. Bagula, Mar 30 2005

Keywords

Crossrefs

Programs

  • Mathematica
    Hofstadter[n_Integer? Positive] := Hofstadter[n] = Hofstadter[n - Hofstadter[n - 1]] + Hofstadter[n - Hofstadter[n - 2]];
    Hofstadter[0] = Hofstadter[1] = 1;
    s[1] = {1, 2}; s[2] = {1, 3}; s[3] = {1};
    t[a_] := Join[a, Flatten[s /@ a]];
    p[0] = {1}; p[1] = t[{1}];
    p[n_] := t[p[n - 1]];
    Flatten[Table[p[If[n > 0, Hofstadter[n], n]], {n, 0, 7}]]

Formula

Involves substitutions 1-> {1, 2}, 2->{1, 3}, 3->1.

A104231 Triangle read by rows, based on the morphism f: 1->2, 2->3, 3->{3,3,5,4}, 4->5, 5->6, 6->{6,6,2,1}. First row is 1. If current row is a,b,c,..., then the next row is a,b,c,...,f(a),f(b),f(c),...

Original entry on oeis.org

1, 1, 2, 1, 2, 2, 3, 1, 2, 2, 3, 2, 3, 3, 3, 3, 5, 4, 1, 2, 2, 3, 2, 3, 3, 3, 3, 5, 4, 2, 3, 3, 3, 3, 5, 4, 3, 3, 3, 5, 4, 3, 3, 5, 4, 3, 3, 5, 4, 3, 3, 5, 4, 6, 5, 1, 2, 2, 3, 2, 3, 3, 3, 3, 5, 4, 2, 3, 3, 3, 3, 5, 4, 3, 3, 3, 5, 4, 3, 3, 5, 4, 3, 3, 5, 4, 3, 3, 5, 4, 6, 5, 2, 3, 3, 3, 3, 5, 4, 3, 3, 3, 5, 4, 3
Offset: 0

Views

Author

Roger L. Bagula, Apr 02 2005

Keywords

Comments

This substitution was suggested by looking at output of the symbols of an actual Kenyon border tiling program.

Crossrefs

Programs

  • Mathematica
    s[n_] := n /. {1 -> 2, 2 -> 3, 3 -> {3, 3, 5, 4}, 4 -> 5, 5 -> 6, 6 -> {6, 6, 2, 1}}; t[a_] := Join[a, Flatten[s /@ a]]; Flatten[ NestList[t, {1}, 5]]

A104232 Triangle read by rows, based on the morphism f: 1->2, 2->3, 3->{2,1}. First row is 1. If current row is a,b,c,..., then the next row is a,b,c,...,f(a),f(b),f(c),...

Original entry on oeis.org

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

Views

Author

Roger L. Bagula, Apr 02 2005

Keywords

Comments

This substitution was suggested by looking at the Kenyon border tiling substitutions.

Crossrefs

Cf. A073058.

Programs

  • Mathematica
    s[n_] := n /. {1 -> 2, 2 -> 3, 3 -> {2, 1}}; t[a_] := Join[a, Flatten[s /@ a]]; Flatten[ NestList[t, {1}, 6]]
Previous Showing 11-20 of 25 results. Next