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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A003137 Write n in base 3 and juxtapose.

Original entry on oeis.org

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

Views

Author

Keywords

Comments

An irregular table in which the n-th row lists the base-3 digits of n, see A007089. - Jason Kimberley, Dec 07 2012
The base-3 Champernowne constant (A077771): it is normal in base 3. - Jason Kimberley, Dec 07 2012

Examples

			1,
2,
1,0,
1,1,
1,2,
2,0,
2,1,
2,2,
1,0,0,
1,0,1,.... _R. J. Mathar_, Aug 16 2021
		

References

  • N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Crossrefs

Tables in which the n-th row lists the base b digits of n: A030190 and A030302 (b=2), this sequence and A054635 (b=3), A030373 (b=4), A031219 (b=5), A030548 (b=6), A030998 (b=7), A031035 and A054634 (b=8), A031076 (b=9), A007376 and A033307 (b=10). - Jason Kimberley, Dec 06 2012
Cf. A081604 (row lengths), A053735 (row sums), A030341 (rows reversed), A077771, A007089.

Programs

  • Haskell
    a003137 n k = a003137_tabf !! (n-1) !! k
    a003137_row n = a003137_tabf !! (n-1)
    a003137_tabf = map reverse $ tail a030341_tabf
    a003137_list = concat a003137_tabf
    -- Reinhard Zumkeller, Feb 21 2013
    
  • Magma
    &cat[Reverse(IntegerToSequence(n,3)):n in[1..31]]; // Jason Kimberley, Dec 07 2012
    
  • Mathematica
    Flatten@ IntegerDigits[ Range@ 40, 3] (* or *)
    almostNatural[n_, b_] := Block[{m = 0, d = n, i = 1, l, p}, While[m <= d, l = m; m = (b - 1) i*b^(i - 1) + l; i++]; i--; p = Mod[d - l, i]; q = Floor[(d - l)/i] + b^(i - 1); If[p != 0, IntegerDigits[q, b][[p]], Mod[q - 1, b]]]; Array[ a[#, 3] &, 105] (* Robert G. Wilson v, Jul 01 2014 *)
  • Python
    from itertools import count, islice
    from sympy.ntheory.factor_ import digits
    def A003137_gen(): return (d for m in count(1) for d in digits(m,3)[1:])
    A003137_list = list(islice(A003137_gen(),30)) # Chai Wah Wu, Jan 07 2022

Extensions

More terms from Larry Reeves (larryr(AT)acm.org), Sep 25 2000

A030373 Write n in base 4 and juxtapose.

Original entry on oeis.org

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

Views

Author

Keywords

Comments

An irregular table in which the n-th row lists the base-4 digits of n. - Jason Kimberley, Nov 26 2012
The base-4 Champernowne constant: it is normal in base 4. - Jason Kimberley, Nov 26 2012

Examples

			1;
2;
3;
1,0;
1,1;
1,2;
1,3;
2,0;
2,1;
2,2;
...
3,3;
1,0,0;
1,0,1;
1,0,2;
1,0,3;
1,1,0; ....
		

Crossrefs

Tables in which the n-th row lists the base b digits of n: A030190 and A030302 (b=2), A003137 and A054635 (b=3), this sequence (b=4), A031219 (b=5), A030548 (b=6), A030998 (b=7), A031035 and A054634 (b=8), A031076 (b=9), A007376 and A033307 (b=10). - Jason Kimberley, Dec 06 2012

Programs

  • Magma
    &cat[Reverse(IntegerToSequence(n,4)):n in[1..31]]; // Jason Kimberley, Dec 07 2012
    
  • Mathematica
    Flatten[IntegerDigits[Range[40],4]] (* Harvey P. Dale, Aug 23 2011 *)
  • Python
    from itertools import count, chain, islice
    from sympy.ntheory.factor_ import digits
    def A030373_gen(): return chain.from_iterable(digits(m, 4)[1:] for m in count(1))
    A030373_list = list(islice(A030373_gen(), 30)) # Chai Wah Wu, Jan 07 2022

A031076 Write n in base 9 and juxtapose.

Original entry on oeis.org

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

Views

Author

Keywords

Comments

An irregular table in which the n-th row lists the base-9 digits of n. - Jason Kimberley, Dec 07 2012
The base-9 Champernowne constant: it is normal in base 9. - Jason Kimberley, Dec 07 2012

Crossrefs

Tables in which the n-th row lists the base b digits of n: A030190 and A030302 (b=2), A003137 and A054635 (b=3), A030373 (b=4), A031219 (b=5), A030548 (b=6), A030998 (b=7), A031035 and A054634 (b=8), this sequence (b=9), A007376 and A033307 (b=10). - Jason Kimberley, Dec 06 2012

Programs

  • Haskell
    a031076 n = a031076_list !! (n-1)
    a031076_list = concat $ map reverse $ tail a031087_tabf
    -- Reinhard Zumkeller, Jul 07 2015
    
  • Magma
    &cat[Reverse(IntegerToSequence(n,9)):n in[1..31]]; // Jason Kimberley, Dec 07 2012
    
  • Mathematica
    Flatten@ IntegerDigits[ Range@ 55, 9] (* or *)
    almostNatural[n_, b_] := Block[{m = 0, d = n, i = 1, l, p}, While[m <= d, l = m; m = (b - 1) i*b^(i - 1) + l; i++]; i--; p = Mod[d - l, i]; q = Floor[(d - l)/i] + b^(i - 1); If[p != 0, IntegerDigits[q, b][[p]], Mod[q - 1, b]]]; Array[ almostNatural[#, 9] &, 105] (* Robert G. Wilson v, Jul 01 2014 *)
  • Python
    from itertools import count, chain, islice
    from sympy.ntheory.factor_ import digits
    def A031076_gen(): return chain.from_iterable(digits(m,9)[1:] for m in count(1))
    A031076_list = list(islice(A031076_gen(),30)) # Chai Wah Wu, Jan 07 2022

A030998 Write n in base 7 and juxtapose.

Original entry on oeis.org

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

Views

Author

Keywords

Comments

An irregular table in which the n-th row lists the base-7 digits of n. - Jason Kimberley, Dec 07 2012
The base-7 Champernowne constant: it is normal in base 7. - Jason Kimberley, Dec 07 2012

Crossrefs

Tables in which the n-th row lists the base b digits of n: A030190 and A030302 (b=2), A003137 and A054635 (b=3), A030373 (b=4), A031219 (b=5), A030548 (b=6), this sequence (b=7), A031035 and A054634 (b=8), A031076 (b=9), A007376 and A033307 (b=10). - Jason Kimberley, Dec 06 2012
Cf. A007093.

Programs

  • Magma
    [0]cat &cat[Reverse(IntegerToSequence(n,7)):n in[1..31]]; // Jason Kimberley, Dec 07 2012
    
  • Mathematica
    Flatten[IntegerDigits[#,7]&/@Range[0,60]]  (* Harvey P. Dale, Mar 04 2011 *)
    almostNatural[n_, b_] := Block[{m = 0, d = n, i = 1, l, p}, While[m <= d, l = m; m = (b - 1) i*b^(i - 1) + l; i++]; i--; p = Mod[d - l, i]; q = Floor[(d - l)/i] + b^(i - 1); If[p != 0, IntegerDigits[q, b][[p]], Mod[q - 1, b]]]; Array[ almostNatural[#, 7] &, 105, 0] (* Robert G. Wilson v, Jun 29 2014 *)
  • Python
    from itertools import count, chain, islice
    from sympy.ntheory.factor_ import digits
    def A030998_gen(): return chain.from_iterable(digits(m, 7)[1:] for m in count(0))
    A030998_list = list(islice(A030998_gen(), 30)) # Chai Wah Wu, Jan 07 2022

A031035 Write n in base 8 and juxtapose.

Original entry on oeis.org

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

Views

Author

Keywords

Comments

Apart from the initial term, identical to A054634.
Should not be merged with A054634 because there are many sequences which depend on this sequence starting with a 1. - N. J. A. Sloane, Jan 30 2010
An irregular table in which the n-th row lists the base-8 digits of n. - Jason Kimberley, Dec 07 2012
The base-8 Champernowne constant: it is normal in base 8. - Jason Kimberley, Dec 07 2012

Crossrefs

Tables in which the n-th row lists the base b digits of n: A030190 and A030302 (b=2), A003137 and A054635 (b=3), A030373 (b=4), A031219 (b=5), A030548 (b=6), A030998 (b=7), this sequence and A054634 (b=8), A031076 (b=9), A007376 and A033307 (b=10). - Jason Kimberley, Dec 06 2012
Cf. A007094.

Programs

  • Magma
    &cat[Reverse(IntegerToSequence(n,8)):n in[1..31]]; // Jason Kimberley, Dec 07 2012
    
  • Maple
    seq(op(ListTools:-Reverse(convert(n,base,8))),n=1..100); # Robert Israel, Nov 12 2024
  • Mathematica
    Flatten[ IntegerDigits[ Range[40], 8]] (* or *)
    almostNatural[n_, b_] := Block[{m = 0, d = n, i = 1, l, p}, While[m <= d, l = m; m = (b - 1) i*b^(i - 1) + l; i++]; i--; p = Mod[d - l, i]; q = Floor[(d - l)/i] + b^(i - 1); If[p != 0, IntegerDigits[q, b][[p]], Mod[q - 1, b]]]; Array[ almostNatural[#, 8] &, 105] (* Robert G. Wilson v, Jun 29 2014 *)
  • Python
    from itertools import count, islice
    from sympy.ntheory.factor_ import digits
    def A031035_gen(): return (d for m in count(1) for d in digits(m,8)[1:])
    A031035_list = list(islice(A031035_gen(),30)) # Chai Wah Wu, Jan 07 2022

A054634 Champernowne sequence: write n in base 8 and juxtapose.

Original entry on oeis.org

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

Views

Author

N. J. A. Sloane, Apr 16 2000

Keywords

Comments

Apart from the initial term, identical to A031035.
Should not be merged with A031035 because there are many sequences which depend on the latter starting with a 1. - N. J. A. Sloane, Jan 30 2010
An irregular table in which the n-th row lists the base-8 digits of n. - Jason Kimberley, Dec 07 2012
The base-8 Champernowne constant: it is normal in base 8. - Jason Kimberley, Dec 07 2012

Crossrefs

Tables in which the n-th row lists the base b digits of n: A030190 and A030302 (b=2), A003137 and A054635 (b=3), A030373 (b=4), A031219 (b=5), A030548 (b=6), A030998 (b=7), A031035 and this sequence (b=8), A031076 (b=9), A007376 and A033307 (b=10). - Jason Kimberley, Dec 06 2012

Programs

  • Magma
    [0]cat &cat[Reverse(IntegerToSequence(n,8)):n in[1..31]]; // Jason Kimberley, Dec 07 2012
    
  • Mathematica
    Flatten[ IntegerDigits[ Range[0, 40], 8]] (* or *)
    almostNatural[n_, b_] := Block[{m = 0, d = n, i = 1, l, p}, While[m <= d, l = m; m = (b - 1) i*b^(i - 1) + l; i++]; i--; p = Mod[d - l, i]; q = Floor[(d - l)/i] + b^(i - 1); If[p != 0, IntegerDigits[q, b][[p]], Mod[q - 1, b]]]; Array[ almostNatural[#, 8] &, 105, 0] (* Robert G. Wilson v, Jun 29 2014 *)
  • Python
    from itertools import count, chain, islice
    from sympy.ntheory.factor_ import digits
    def A054634_gen(): return chain.from_iterable(digits(m, 8)[1:] for m in count(0))
    A054634_list = list(islice(A054634_gen(), 30)) # Chai Wah Wu, Jan 07 2022

A066717 The continued fraction for the "binary" Champernowne constant.

Original entry on oeis.org

0, 1, 6, 3, 1, 6, 5, 3, 3, 1, 6, 4, 1, 3, 298, 1, 6, 1, 1, 3, 285, 7, 2, 4, 1, 2, 1, 2, 1, 1, 4534532, 1, 4, 5, 1, 2, 1, 7, 1, 16, 1, 4, 1, 5, 5, 1, 5, 1, 4, 1, 2, 1, 5, 3, 2, 38, 2, 12, 1, 15, 2, 6, 3, 30, 4682854730443938, 1, 1, 68, 1, 6, 5, 4, 4, 1, 2, 1, 1, 1, 1, 2, 22, 1, 2, 7, 1, 2
Offset: 0

Views

Author

Robert G. Wilson v, Jan 14 2002

Keywords

Crossrefs

Cf. A030190 & A066716 (binary & decimal digits of the binary Champernowne constant), A033307 (decimal Champernowne constant).
Cf. A054635, A077771, A077772: base 3, decimals and continued fraction of ternary Champernowne constant.

Programs

  • Mathematica
    a = {}; Do[a = Append[a, IntegerDigits[n, 2]], {n, 1, 10^3} ]; ContinuedFraction[ N[ FromDigits[ {Flatten[a], 0}, 2], 500]]
    almostNatural[n_, b_] :=  Block[{m = 0, d = n, i = 1, l, p}, While[m <= d, l = m; m = (b - 1) i*b^(i - 1) + l; i++]; i--; p = Mod[d - l, i]; q = Floor[(d - l)/i] + b^(i - 1); If[p != 0, IntegerDigits[q, b][[p]], Mod[q - 1, b]]]; Take[ ContinuedFraction[ FromDigits[ {Array[almostNatural[#, 2] &, 20000], 0}, 2]], 100] (* Robert G. Wilson v, Jul 21 2014 *)
  • PARI
    A066717(b=2,t=1.,s=b)={contfrac(sum(n=1,default(realprecision)*2.303\log(b)+1, nM. F. Hasler, Oct 25 2019

A077772 Continued fraction expansion of the ternary Champernowne constant.

Original entry on oeis.org

0, 1, 1, 2, 37, 1, 162, 1, 1, 1, 3, 1, 7, 1, 9, 2, 3, 1, 3068518062211324, 2, 1, 2, 6, 13, 1, 2, 1, 3, 1, 10, 1, 21, 1, 1, 4, 3, 577, 1, 1079268324684171943515797470873767312825026176345571319042096689270, 1, 1, 1, 3, 4, 21, 3, 1, 9, 1
Offset: 0

Views

Author

Eric W. Weisstein, Nov 15 2002

Keywords

Crossrefs

Cf. A054635 (ternary digits), A077771 (decimals).
Cf. A030190, A066716, A066717: binary digits, decimals and continued fraction of the binary Champernowne constant; A033307: decimal Champernowne constant.

Programs

  • Mathematica
    almostNatural[n_, b_] :=  Block[{m = 0, d = n, i = 1, l, p}, While[m <= d, l = m; m = (b - 1) i*b^(i - 1) + l; i++]; i--; p = Mod[d - l, i]; q = Floor[(d - l)/i] + b^(i - 1); If[p != 0, IntegerDigits[q, b][[p]], Mod[q - 1, b]]]; Take[ ContinuedFraction[ FromDigits[ {Array[almostNatural[#, 3] &, 20000], 0}, 3]], 100] (* Robert G. Wilson v, Jul 21 2014 *)
  • PARI
    \p 10000
    t=0;r=0.;T=1; for(n=1,1e6,d=#digits(n,3);t+=d;T*=3^d;r+=n/T;if(t>20959, return)); v=contfrac(r); v[1..30] \\ Charles R Greathouse IV, Sep 23 2014
    
  • PARI
    A077772(b=3,t=1.,s=b)={contfrac(sum(n=1,default(realprecision)*2.303/log(b)+1, nM. F. Hasler, Oct 25 2019

A077771 Decimal value of the ternary Champernowne constant.

Original entry on oeis.org

5, 9, 8, 9, 5, 8, 1, 6, 7, 5, 3, 8, 4, 3, 3, 9, 9, 2, 5, 0, 0, 1, 7, 2, 2, 1, 7, 9, 2, 9, 4, 3, 6, 5, 9, 0, 9, 7, 8, 2, 0, 8, 7, 6, 8, 6, 7, 6, 1, 0, 5, 9, 3, 6, 7, 5, 4, 7, 8, 6, 0, 7, 5, 4, 7, 9, 6, 5, 1, 8, 4, 1, 9, 5, 2, 8, 0, 8, 4, 2, 0, 5, 5, 4, 0, 7, 2, 1, 1, 0, 8, 0, 5, 2, 7, 9, 6, 4, 1, 5, 7
Offset: 0

Views

Author

Eric W. Weisstein, Nov 15 2002

Keywords

Comments

The first 99 digits form a prime. - Jonathan Vos Post, Nov 11 2004
This constant is 3-normal. - Charles R Greathouse IV, Feb 06 2015

Examples

			0.598958167538433992500172217929...
		

Crossrefs

Cf. A054635 (base 3 digits), A077772 (continued fraction).
Cf. A030190, A066716, A066717: binary digits, decimals and continued fraction of the binary Champernowne constant; A033307: decimal Champernowne constant.

Programs

  • Mathematica
    First[RealDigits[ChampernowneNumber[3], 10, 100]] (* Paolo Xausa, May 03 2024 *)
  • PARI
    A077771(b=3,t=1.,s=b)={sum(n=1, default(realprecision)*2.303\log(b)+1, nM. F. Hasler, Oct 25 2019

A055144 The first n digits of the juxtaposition of the base-3 numbers converted to decimal.

Original entry on oeis.org

1, 5, 16, 48, 145, 436, 1309, 3929, 11789, 35367, 106103, 318310, 954932, 2864798, 8594395, 25783185, 77349555, 232048666, 696145998, 2088437995, 6265313986, 18795941958, 56387825876, 169163477629, 507490432888, 1522471298664
Offset: 1

Views

Author

Patrick De Geest, Apr 15 2000

Keywords

Examples

			1 (1); 12 (5); 121 (16); 1210 (48); 12101 (145); 121011 (436); ...
		

Crossrefs

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