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 1-5 of 5 results.

A238271 Decimal expansion of sum(n>=1, mu(n)/3^n ).

Original entry on oeis.org

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

Views

Author

Robert G. Wilson v, Feb 21 2014

Keywords

Comments

Suggested by a posting to SeqFan list by Alonso Del Arte at 15:35 on Aug 09 2012.

Examples

			=0.1819953867026338878278001003005655732263449801353830617592494771...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[ Sum[ N[ MoebiusMu[n] 3^-n, 128], {n, 300}], 10, 111][[1]]

A344432 a(n) = Sum_{k=1..n} mu(k) * 2^(n - k).

Original entry on oeis.org

0, 1, 1, 1, 2, 3, 7, 13, 26, 52, 105, 209, 418, 835, 1671, 3343, 6686, 13371, 26742, 53483, 106966, 213933, 427867, 855733, 1711466, 3422932, 6845865, 13691730, 27383460, 54766919, 109533837, 219067673, 438135346, 876270693, 1752541387, 3505082775, 7010165550
Offset: 0

Views

Author

Seiichi Manyama, May 19 2021

Keywords

Crossrefs

Programs

  • Mathematica
    a[n_] := Sum[MoebiusMu[k] * 2^(n-k), {k,1,n}]; Array[a, 40] (* Amiram Eldar, May 19 2021 *)
  • PARI
    a(n) = sum(k=1, n, moebius(k)*2^(n-k));
    
  • PARI
    my(N=40, x='x+O('x^N)); concat(0, Vec(sum(k=1, N, moebius(k)*x^k)/(1-2*x)))
    
  • PARI
    a(n) = if(n==0, 0, 2*a(n-1)+moebius(n));

Formula

G.f.: (Sum_{k>=1} mu(k) * x^k) / (1 - 2*x).
a(n) = 2 * a(n-1) + mu(n) for n > 0.
a(n) ~ A238270 * 2^n. - Vaclav Kotesovec, May 19 2021

A181673 Decimal expansion of Sum_{n>=1} moebius(n)*(1/10)^n.

Original entry on oeis.org

0, 8, 8, 9, 9, 0, 9, 0, 0, 0, 8, 9, 9, 1, 0, 9, 8, 9, 9, 0, 1, 0, 9, 0, 0, 0, 9, 9, 8, 8, 9, 0, 1, 1, 0, 9, 9, 1, 0, 9, 8, 8, 9, 0, 0, 0, 9, 0, 0, 0, 0, 9, 9, 0, 1, 0, 1, 0, 8, 9, 9, 1, 0, 0, 0, 8, 9, 0, 0, 8, 8, 9, 9, 1, 0, 0, 0, 8, 9, 0, 0, 0, 9, 0, 1, 1, 0, 9, 9
Offset: 0

Views

Author

Mats Granvik, Nov 04 2010

Keywords

Examples

			0.088990900089910989901090009988901109910...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[ Sum[ N[ MoebiusMu[n] 10^-n, 128], {n, 120}], 10, 111][[1]] (* Robert G. Wilson v, Feb 21 2014 *)
  • PARI
    sum(n=1,default(realprecision)+1,moebius(n)/10.^n) \\ Charles R Greathouse IV, Feb 13 2011

Extensions

Corrected by Charles R Greathouse IV, May 27 2015

A238273 Decimal expansion of the Sum_{n>=1} mu(n)/n^n where mu is the Moebius function.

Original entry on oeis.org

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

Views

Author

Robert G. Wilson v, Feb 21 2014

Keywords

Comments

Suggested by a posting to SeqFan list by Alonso Del Arte at 15:35 on Aug 09 2012.

Examples

			0.71266318226428345712160416832186125060530702174716136907035050632955566121...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[ Sum[ N[ MoebiusMu[n] 1 n^-n, 128], {n, 100}], 10, 111][[1]]

A380387 Decimal expansion of Sum_{n>=1} lambda(n)/2^n where lambda is the Liouville function (A008836).

Original entry on oeis.org

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

Views

Author

Friedjof Tellkamp, Jan 23 2025

Keywords

Comments

Close in value to log(zeta(Pi)) = 0.162324388... (A300892).

Examples

			0.16232463762392978595979733583622409170004837922881594919344293897...
		

Crossrefs

Programs

  • Mathematica
    RealDigits[Sum[N[LiouvilleLambda[n]/ 2^n, 128], {n, 300}], 10, 86][[1]]
  • PARI
    suminf(n=1, (-1)^bigomega(n)/2^n) \\ Michel Marcus, Jan 23 2025

Formula

Equals 2*A343784 - 1. - Hugo Pfoertner, Jan 25 2025
Showing 1-5 of 5 results.