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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A246354 Rectangular array: T(n,k) is the position in the infinite Fibonacci word s = A003849 at which the block s(1)..s(n) occurs for the k-th time.

Original entry on oeis.org

1, 3, 1, 4, 4, 1, 6, 6, 4, 1, 8, 9, 6, 6, 1, 9, 12, 9, 9, 6, 1, 11, 14, 12, 14, 9, 6, 1, 12, 17, 14, 19, 14, 9, 9, 1, 14, 19, 17, 22, 19, 14, 14, 9, 1, 16, 22, 19, 27, 22, 19, 22, 14, 9, 1, 17, 25, 22, 30, 27, 22, 30, 22, 14, 9, 1, 19, 27, 25, 35, 30, 27, 35
Offset: 1

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Author

Clark Kimberling, Aug 24 2014

Keywords

Comments

Assuming that every row of T is infinite, each row contains the next row as a proper subsequence. Row 1 of A246354 and row 1 of A246355 partition the positive integers.

Examples

			The lower Wythoff sequence, A000201 gives the positions of 0 in A003849, which begins thus:  0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1, 0, 1, 0, 0, 1.  For n = 1, the block s(1)..s(1) is simply 0, which occurs at positions 1,3,4,6,8,... as in row 1 of T.  For n = 5, the block s(1)..s(5) is 0,1,0,0,1, which occurs at positions 1,6,9,14,19, ...
The first 7 rows follow:
1 .. 3 .. 4 ... 6 ... 8 ... 9 ... 11 .. 12 ...
1 .. 4 .. 6 ... 9 ... 12 .. 14 .. 17 .. 19 ...
1 .. 4 .. 6 ... 9 ... 12 .. 14 .. 17 .. 19 ...
1 .. 6 .. 9 ... 14 .. 19 .. 22 .. 27 .. 30 ...
1 .. 6 .. 9 ... 14 .. 19 .. 22 .. 27 .. 30 ...
1 .. 6 .. 9 ... 14 .. 19 .. 22 .. 27 .. 30 ...
1 .. 9 .. 14 .. 22 .. 30 .. 35 .. 43 .. 48 ...
		

Crossrefs

Programs

  • Mathematica
    z = 1000; s = Flatten[Nest[{#, #[[1]]} &, {0, 1}, 12]]; Flatten[Position[s, 0]];  b[m_, n_] := b[m, n] = Take[s, {m, n}]; z1 = 500; z2 = 12; t[k_] := t[k] = Take[Select[Range[1, z1], b[#, # + k] == b[1, 1 + k] &], z2]; Column[Table[t[k], {k, 0, z2}]] (* A246354, array *)
    w[n_, k_] := t[n][[k + 1]]; Table[w[n - k, k], {n, 0, z2 - 1}, {k, n, 0, -1}] // Flatten (*  A246354, sequence *)

Formula

First row: A000201 (lower Wythoff numbers);
next 2 rows: A003622 (Wythoff AA numbers);
next 3 rows: A134859 (Wythoff AAA numbers);
next 5 rows: A151915 (Wythoff AAAA numbers).
(The patterns continue; in particular the number of identical consecutive rows is always a Fibonacci number, as in A000045.)

A276757 Infinite Fibonacci word on the alphabet {1,2,3,4,5}.

Original entry on oeis.org

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

Views

Author

Michel Dekking, Sep 17 2016

Keywords

Comments

Start with the infinite Fibonacci word A003849, which is 0100101001001010010... and replace each 0 by 1,2,3 and each 1 by 4,5.
The unique fixed point of the 4-block Fibonacci substitution 1 -> 12, 2 -> 3, 3 -> 45, 4 -> 12, 5 -> 3. Here the 4-blocks are coded as 0100 <-> 1, 1001 <-> 2, 0010 <-> 3, 0101 <-> 4, 1010 <-> 5.

Crossrefs

Formula

Let A(n) = floor(n*phi), B(n) = n + floor(n*phi), i.e., A and B are the lower and upper Wythoff sequences, A = A000201, B = A001950. Then a(n) = 1 if n = A(A(A(k))) for some k; a(n) = 2 if n = B(A(k)) for some k; a(n) = 3 if n = A(B(k)) for some k; a(n) = 4 if n = A(A(B(k))) for some k; a(n) = 5 if n = B(B(k)) for some k.

A340244 Wythoff-B array read by antidiagonals.

Original entry on oeis.org

4, 7, 12, 11, 20, 17, 18, 32, 28, 25, 29, 52, 45, 41, 33, 47, 84, 73, 66, 54, 38, 76, 136, 118, 107, 87, 62, 46, 123, 220, 191, 173, 141, 100, 75, 51, 199, 356, 309, 280, 228, 162, 121, 83, 59, 322, 576, 500, 453, 369, 262, 196, 134, 96, 67, 521, 932, 809
Offset: 1

Views

Author

Clark Kimberling, Jan 02 2021

Keywords

Comments

The Wythoff array, A134859, consists of columns AA, BA, ABA, BBA, ABBA, BBBA, ... The Wythoff-B array consists of columns AAB, BAB, ABAB, BBAB, ABBAB, BBBAB, ... , formed by suffixing B to the column designations for A134859. Column k shows the numbers whose Zeckendorf representation has least terms F(k+1) and F(k+2), where F = A000045, the Fibonacci numbers. The rows are interspersed, in the sense that the order array (A340245) of the Wythoff-B array is an interspersion.

Examples

			Corner:
   4    7    11    18    29    47   76     123    199
  12   20    32    52    84   136   220    356    576
  17   28    45    73   118   191   309    500    809
  25   41    66   107   173   280   453    733   1186
  33   54    87   141   228   369   597    966   1563
  38   62   100   162   262   424   686   1110   1796
  46   75   121   196   317   513   830   1343   2173
  51   83   134   217   351   568   919   1487   2406
		

Crossrefs

Programs

  • Mathematica
    r = GoldenRatio; f[n_] := Fibonacci[n];
    a[n_] := Floor[r*n]; b[n_] := Floor[r^2*n];
    c[n_] := a[a[b[n]]]; d[n_] := b[a[b[n]]];
    w[n_, k_] := f[k - 2] c[n] + f[k - 1] d[n];
    Grid[Table[w[n, k], {n, 1, 15}, {k, 1, 15}]] (* A340244 array *)
    Table[w[n - k + 1, k], {n, 15}, {k, n, 1, -1}] // Flatten  (* A340244 sequence *)

Formula

For n >=1 and k >= 1, w(n,k) = F(k-2)*A(A(B(n))) + F(k-1)*B(A(B(n))), where A(n) = floor(n*phi), B(n) = floor(n*phi^2); i.e., A = A000201, B= A001950, these being the lower and upper Wythoff sequences. (Note that F(-1) = 1, F(0) = 0.)

A372302 Numbers k for which the Zeckendorf representation A014417(k) ends with "1001".

Original entry on oeis.org

6, 19, 27, 40, 53, 61, 74, 82, 95, 108, 116, 129, 142, 150, 163, 171, 184, 197, 205, 218, 226, 239, 252, 260, 273, 286, 294, 307, 315, 328, 341, 349, 362, 375, 383, 396, 404, 417, 430, 438, 451, 459, 472, 485, 493, 506, 519, 527, 540, 548, 561, 574, 582, 595, 603
Offset: 1

Views

Author

A.H.M. Smeets, Apr 25 2024

Keywords

Crossrefs

Tree of Zeckendorf subsequences of positive integers partitioned by their suffix part S (except initial term or offset in some cases). $ is the empty string. length(S) =
0 1 2 3 4 5 6 7
----------------------------------------------------------------------
$: 0: 00: 000: 0000: 00000: 000000:
100000: 0100000:
A035340 <------
10000:
1000: 01000:
A035338 <------
10: 010: 0010:
A035336 <------ A134861
1010: 01010:
A134863 <------
100: 0100:
A035337 <------
1: 01: 001: 0001:
1001: 01001:
A372302 <------
101: 0101:
A134860 <------
Suffixes 10^n, where ^ means n times repeated concatenation, are the (n+1)-th columns in the Wythoff array A083412 and A035513 (n >= 0).

Formula

Equals {A134859}\{A151915}.
a(n) = A134863(n) - 1 = A035338(n) + 1.
a(n) = a(n-1) + 8 + 5*A005614(n-2) = a(n-1) + F(6) + F(5)*A005614(n-2), n > 1, where F(k) is the k-th Fibonacci number (A000045).
Previous Showing 11-14 of 14 results.