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.

A105234 Central column of a Moebius-binomial triangle.

Original entry on oeis.org

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

Views

Author

Paul Barry, Apr 14 2005

Keywords

Comments

Central column of A105586. Partial sums are A105235.

Crossrefs

Programs

  • Mathematica
    a[n_]:=Binomial[Abs[MoebiusMu[2n]],Abs[MoebiusMu[n]]];Table[a[n],{n,0,100}] (* James C. McMahon, Jan 22 2024 *)
  • PARI
    A105234(n) = if(n<2,1,binomial(abs(moebius(2*n)), abs(moebius(n)))); \\ Antti Karttunen, Sep 13 2017

Formula

a(n) = binomial(abs(mu(2n)), abs(mu(n))).

A105587 Row sums of a Möbius-binomial triangle.

Original entry on oeis.org

1, 2, 3, 4, 1, 6, 7, 8, 2, 3, 11, 12, 4, 14, 15, 16, 5, 18, 6, 20, 7, 22, 23, 24, 8, 9, 27, 10, 11, 30, 31, 32, 12, 34, 35, 36, 13, 38, 39, 40, 14, 42, 43, 44, 15, 16, 47, 48, 17, 18, 19, 52, 20, 54, 21, 56, 22, 58, 59, 60, 23, 62, 63, 24, 25, 66, 67, 68, 26, 70, 71, 72, 27, 74, 75
Offset: 0

Views

Author

Paul Barry, Apr 14 2005

Keywords

Comments

a(n) = n unless n is nonsquarefree, in which case a(n) = rank of n as a nonsquarefree number. Row sums of A105586.

Examples

			a(4) = 1 since 4 is the first nonsquarefree number;
a(8) = 2 since 8 is the second nonsquarefree number.
		

Formula

a(n) = Sum_{k=0..n} binomial(abs(mu(n)), abs(mu(k))).

A105588 Diagonal sums of a Moebius-binomial triangle.

Original entry on oeis.org

1, 1, 2, 2, 2, 2, 3, 3, 4, 3, 4, 4, 5, 5, 5, 5, 7, 7, 7, 7, 9, 8, 9, 8, 11, 9, 10, 9, 11, 10, 10, 10, 13, 12, 13, 12, 17, 14, 14, 14, 18, 16, 16, 17, 20, 17, 16, 16, 21, 18, 17, 17, 23, 20, 20, 18, 24, 22, 23, 21, 26, 23, 23, 22, 27, 24, 24, 24, 30, 25, 26, 24, 34, 27, 28, 26, 33, 28
Offset: 0

Views

Author

Paul Barry, Apr 14 2005

Keywords

Comments

Diagonal sums of A105586.

Crossrefs

Formula

a(n) = Sum_{k=0..floor(n/2)} binomial(abs(mu(n-k)), abs(mu(k))).

A105589 Inverse of a Moebius-binomial triangle.

Original entry on oeis.org

1, -1, 1, 0, -1, 1, 0, 0, -1, 1, 0, 0, 0, 0, 1, 0, 0, 0, -1, -1, 1, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, -1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0, 0, 0, 1, 0, 0, -1, 0, -1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, -1, 1, 0, 0
Offset: 0

Views

Author

Paul Barry, Apr 14 2005

Keywords

Comments

Inverse of A105586. The inverse exists since binomial(abs(mu(n)),abs(mu(n)))=1 for all n.
Showing 1-4 of 4 results.