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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A071153 Łukasiewicz word for each rooted plane tree (interpretation e in Stanley's exercise 19) encoded by A014486 (or A063171), with the last leaf implicit, i.e., these words are given without the last trailing zero, except for the null tree which is encoded as 0.

Original entry on oeis.org

0, 1, 20, 11, 300, 201, 210, 120, 111, 4000, 3001, 3010, 2020, 2011, 3100, 2101, 2200, 1300, 1201, 2110, 1210, 1120, 1111, 50000, 40001, 40010, 30020, 30011, 40100, 30101, 30200, 20300, 20201, 30110, 20210, 20120, 20111, 41000, 31001, 31010
Offset: 0

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Author

Antti Karttunen, May 14 2002

Keywords

Comments

Note: this finite decimal representation works only up to the 6917th term, as the 6918th such word is already (10,0,0,0,0,0,0,0,0,0). The sequence A071154 shows the initial portion of this sequence sorted.

Examples

			The 11th term of A063171 is 10110010, corresponding to parenthesization ()(())(), thus its Łukasiewicz word is 3010. The 18th term of A063171 is 11011000, corresponding to parenthesization (()(())), thus its Łukasiewicz word is 1201. I.e., in the latter example there is one list on the top-level, which in turn contains two sublists, of which the first is zero elements long and the second is a sublist containing one empty sublist (the last zero is omitted).
		

Crossrefs

For n >= 1, the number of zeros in the term a(n) is given by A057514(n)-1.
The first digit of each term is given by A057515.
Corresponding factorial walk encoding: A071155 (A071157, A071159).
a(n) = A079436(n)/10.

A071159 Integers whose decimal expansion start with 1, do not contain zeros and each successive digit to the right is at most one greater than the previous digit.

Original entry on oeis.org

1, 11, 12, 111, 112, 121, 122, 123, 1111, 1112, 1121, 1122, 1123, 1211, 1212, 1221, 1222, 1223, 1231, 1232, 1233, 1234, 11111, 11112, 11121, 11122, 11123, 11211, 11212, 11221, 11222, 11223, 11231, 11232, 11233, 11234, 12111, 12112, 12121
Offset: 1

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Author

Antti Karttunen, May 14 2002

Keywords

Crossrefs

Essentially the same as A071157 but with digits reversed.
Corresponding Łukasiewicz words: A071153.

Programs

  • Maple
    R[1]:= [1]:
    for d from 2 to 6 do
    R[d]:= map(t -> seq(10*t+j,j=1..min((t mod 10)+1,9)), R[d-1])
    od:
    A:= map(op, [seq(R[d],d=1..6)]); # Robert Israel, Jan 31 2017
  • Mathematica
    desQ[n_]:=Module[{idn=IntegerDigits[n]},idn[[1]]==1&&FreeQ[idn,0]&&Max[ Differences[ idn]]<2]; Select[Range[13000],desQ] (* Harvey P. Dale, Feb 19 2017 *)

A071155 The Catalan factorial walks (for each rooted plane tree encoded by A014486) encoded as zero-free numbers in factorial base (A007623).

Original entry on oeis.org

0, 1, 3, 5, 9, 15, 11, 17, 23, 33, 57, 39, 63, 87, 35, 59, 41, 65, 89, 47, 71, 95, 119, 153, 273, 177, 297, 417, 159, 279, 183, 303, 423, 207, 327, 447, 567, 155, 275, 179, 299, 419, 161, 281, 185, 305, 425, 209, 329, 449, 569, 167, 287, 191, 311, 431, 215, 335
Offset: 0

Views

Author

Antti Karttunen, May 14 2002

Keywords

Crossrefs

Same sequence sorted: A071156, expanded in the factorial number system: A071157. Corresponding Łukasiewicz words: A071153.
Cf. A000108 (row lengths), A120695.

A071158 Factorial expansion of A071156.

Original entry on oeis.org

1, 11, 21, 111, 121, 211, 221, 321, 1111, 1121, 1211, 1221, 1321, 2111, 2121, 2211, 2221, 2321, 3211, 3221, 3321, 4321, 11111, 11121, 11211, 11221, 11321, 12111, 12121, 12211, 12221, 12321, 13211, 13221, 13321, 14321, 21111, 21121, 21211
Offset: 1

Views

Author

Antti Karttunen, May 14 2002

Keywords

Comments

Note that this decimal representation works only as long as there does not appear any digit 'ten' or higher in the factorial expansion of A071156.

Crossrefs

a(n) = A007623(A071156(n)) = A071157(A057164(n)).
Showing 1-4 of 4 results.