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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A080826 Successive factors of the Thue-Morse word defined by sequence A001285.

Original entry on oeis.org

122, 12, 1122, 11212212, 1121221122121122, 11212211221211212212112211212212, 1121221122121121221211221121221122121122112122121121221122121122
Offset: 1

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Author

N. J. A. Sloane, Mar 28 2003

Keywords

Comments

The next term is too large to include.

Programs

  • Maple
    A080826:= proc(n) option remember: local l,i: if n = 0 then RETURN([1,2,2]) else l:=A080826(n-1):l := subsop(nops(l)=NULL,l):RETURN([op(l),seq(op(A080826(i)),i=0..n-2)]) fi:end; ds:=s->add(s[j]*10^(nops(s)-j),j=1..nops(s)); seq(ds(A080826(n)),n=0..7); (C. Ronaldo)

Extensions

More terms from C. Ronaldo (aga_new_ac(AT)hotmail.com), Dec 19 2004

A085297 Nonzero residues of Catalan sequence modulo 3; related to the Thue-Morse sequence (A001285).

Original entry on oeis.org

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

Views

Author

Paul D. Hanna, Jun 24 2003

Keywords

Comments

The runs of zeros in between the digit strings are given in A085296.

Crossrefs

Cf. A001285 (Thue-Morse), A000108 (Catalan), A039969 (d-perfect), A085296.

Formula

If a leading '1' is added to the Catalan sequence modulo 3, the only nonzero digit strings are {1, 1, 1, 2, 2, 2} and {2, 2, 2, 1, 1, 1}. Replacing these digit strings with their first digit, {1, 1, 1, 2, 2, 2} -> '1' and {2, 2, 2, 1, 1, 1} -> '2', then omitting all zeros, results in the Thue-Morse sequence.

A225188 Words u such that uu is a factor of the Thue-Morse word A001285.

Original entry on oeis.org

1, 2, 12, 21, 121, 212, 1221, 2112, 122112, 211221, 12212112, 21121221, 122121121221, 211212212112, 1221211221121221, 2112122112212112, 122121122112122112212112, 211212211221211221121221, 12212112211212212112122112212112, 21121221122121121221211221121221, 122121122112122121121221122121121221211221121221, 211212211221211212212112211212212112122112212112
Offset: 1

Views

Author

N. J. A. Sloane, May 05 2013

Keywords

Comments

Consists of 1, 2, 121, 212 and their repeated images under the morphism 1 -> 12, 2 -> 21.
These are the square roots of the words in A225186.
Replacing {1,2} by {0,1} gives the words u such that uu is a factor of A010060.

Crossrefs

A026535 a(n) = t(1+5n) where t = A001285 (Thue-Morse sequence).

Original entry on oeis.org

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

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Crossrefs

Programs

Extensions

Name and Pari corrected by Sean A. Irvine, Oct 06 2019

A029877 Euler transform of Thue-Morse sequence A001285.

Original entry on oeis.org

1, 3, 5, 9, 15, 25, 38, 61, 91, 137, 200, 293, 416, 595, 832, 1161, 1601, 2198, 2983, 4042, 5419, 7245, 9615, 12714, 16703, 21879, 28492, 36989, 47795, 61561, 78956, 100986, 128653, 163461, 206981, 261393
Offset: 0

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Keywords

A029879 Binomial transform of Thue-Morse sequence A001285.

Original entry on oeis.org

1, 3, 7, 14, 27, 52, 100, 192, 371, 728, 1454, 2940, 5968, 12080, 24304, 48608, 96851, 192816, 384562, 769636, 1546226, 3116184, 6290984, 12700832, 25603536, 51479808, 103178992, 206133344, 410674512, 816542272, 1621848640, 3221225472, 6403020371, 12746005088
Offset: 0

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Crossrefs

Cf. A001285.

A029880 Inverse binomial transform of Thue-Morse sequence A001285.

Original entry on oeis.org

1, 1, -1, 0, 3, -10, 24, -48, 83, -126, 170, -208, 240, -272, 272, 0, -1453, 6698, -22050, 60896, -148430, 326404, -653280, 1188640, -1939568, 2730976, -2946256, 1085760, 5849808, -22935520, 57106944, -114213888, 188997203
Offset: 0

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Author

Keywords

Programs

  • Mathematica
    Join[{1}, Table[Differences[Table[ThueMorse[n], {n, 0, m}], m][[1]], {m, 1, 10}]] (* Robert P. P. McKone, Dec 18 2020 *)

A029882 Inverse Moebius transform of Thue-Morse sequence A001285.

Original entry on oeis.org

1, 3, 3, 4, 3, 6, 2, 6, 5, 6, 2, 9, 2, 6, 7, 7, 3, 9, 2, 9, 5, 6, 3, 12, 4, 6, 7, 8, 3, 12, 2, 9, 6, 6, 5, 14, 2, 6, 6, 12, 2, 12, 3, 8, 11, 6, 2, 15, 3, 9, 7, 8, 3, 12, 5, 12, 6, 6, 2, 19, 2, 6, 9, 10, 6, 12, 2, 9, 6, 12, 3, 18, 2, 6, 10
Offset: 0

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A029888 Convolution of Thue-Morse sequence A001285 with primes.

Original entry on oeis.org

2, 7, 15, 25, 42, 62, 87, 116, 152, 192, 241, 296, 356, 425, 491, 569, 660, 754, 851, 960, 1072, 1179, 1311, 1447, 1584, 1745, 1899, 2055, 2220, 2388, 2573, 2778, 2992, 3188, 3415, 3640, 3868, 4125, 4383
Offset: 0

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Author

Keywords

Programs

  • Mathematica
    tm[0] = 1; tm[n_?EvenQ] := tm[n] = tm[n/2]; tm[n_] := tm[n] = 3 - tm[(n-1)/2]; a[n_] := ListConvolve[tm /@ Range[0, n], Prime /@ Range[n+1]] // First; Table[a[n], {n, 0, 38}] (* Jean-François Alcover, Nov 18 2013 *)

A029896 Convolution of Thue-Morse sequence A001285 with A008578 = {1, primes}.

Original entry on oeis.org

1, 4, 9, 16, 27, 43, 63, 89, 118, 153, 193, 243, 297, 358, 427, 492, 571, 661, 755, 853, 961, 1074, 1181, 1312, 1448, 1586, 1747, 1900, 2057, 2221, 2389, 2575, 2780, 2993, 3189, 3417, 3641, 3870, 4127, 4384
Offset: 0

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Keywords

Previous Showing 21-30 of 67 results. Next