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.

Showing 1-4 of 4 results.

A143533 a(n) = A038705(n) - 1.

Original entry on oeis.org

0, 1, 2, 4, 18, 40, 162, 526, 1708, 4838, 13522, 34062
Offset: 1

Views

Author

Eric W. Weisstein, Aug 22 2008

Keywords

Crossrefs

Another version of A038705.
Cf. A143532 (number of decimal digits in n-th term of c.f.).
Cf. A143534 (number of decimal digits in a(n)th term of c.f.).

Extensions

Added a(10) (from Mark Sofroniou), Eric W. Weisstein, Sep 04 2008
Edited by N. J. A. Sloane, Apr 03 2010 to reflect the fact that A038705 is the primary version of this sequence
a(12) from John K. Sikora, Aug 24 2012

A038706 Position of the first occurrence of n in continued fraction for Champernowne constant (A030167).

Original entry on oeis.org

4, 28, 13, 9, 93, 20, 31, 2, 3, 339, 71, 126, 107, 48, 18, 292, 327, 133, 611, 342, 23, 202, 441, 164, 512, 235, 957, 349, 528, 77, 179, 591, 307, 381, 2011, 245, 2435, 187, 1870, 117, 1359, 1071, 762, 4199, 4309, 2308, 4294, 1012, 1501, 3490, 2249, 283
Offset: 1

Views

Author

Hans Havermann, May 01 2000

Keywords

Comments

Only 187 terms of the sequence are known. The position of 188 is > 82328. - Eric W. Weisstein, Jun 29 2013

Crossrefs

A038704 Incrementally largest term in continued fraction for Champernowne constant (A030167).

Original entry on oeis.org

8, 9, 149083
Offset: 1

Views

Author

Hans Havermann, May 01 2000

Keywords

Comments

The next term (a(4)) has 166 digits; a(5) has 2504 digits. - Harvey P. Dale, Sep 18 2016

Crossrefs

Programs

  • Mathematica
    DeleteDuplicates[Block[{$MaxExtraPrecision=10000},ContinuedFraction[ ChampernowneNumber[],50]],GreaterEqual] (* Harvey P. Dale, Apr 02 2023 *)

Extensions

The next term has 166 digits.

A143534 Number of decimal digits in the high-water marks of the terms of the continued fraction of the (base-10) Champernowne constant.

Original entry on oeis.org

0, 1, 1, 6, 166, 2504, 33102, 411100, 4911098, 57111096, 651111094, 7311111092
Offset: 1

Views

Author

Eric W. Weisstein, Aug 22 2008

Keywords

Crossrefs

Cf. A038705 (position of the incrementally largest term in continued fraction for Champernowne constant).
Cf. A143533 (another version of A038705).

Programs

  • Ruby
    puts (4..13).collect {|n| (1..(n-3)).inject(0) {|sum, m| sum+9*m*10**(m-1)}+3-n-2*((1..(n-4)).inject(0) {|sum1, m1| sum1+9*m1*10**(m1-1)}+3-(n-1))-3*(n-2)+4} # John K. Sikora, Aug 25 2012

Formula

It appears that: For N>=3, define NCD(N)=3-N+(sum{m=1..(N-3), m>0} 9*m*10^(m-1)); then for n>=4, a(n) = NCD(n) - 2*NCD(n-1) - 3*(n-2) + 4. - John K. Sikora, Aug 25 2012

Extensions

a(11) = 651111094 (from Mark Sofroniou), Eric W. Weisstein, Sep 04 2008
a(12) = 7311111092 from Eric W. Weisstein, Jun 29 2013
Showing 1-4 of 4 results.