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 1-3 of 3 results.

A105596 a(n) = Sum_{k=0..n} A105595(k)*(-1)^k*A105595(n-k) (interpolated zeros suppressed).

Original entry on oeis.org

1, 5, 13, 17, 25, 25, 33, 21, 9, -15, -23, -3, -11, -31, -47, -35, 5, -47, -83, -75, -211, -295, -267, -267, -99, -107, -159, -415, -347, -679, -279, -583, -395, -839, -1031, -1291, -1139, -1883, -1519, -1643, -855, -1591, -1571, -1851, -1195, -2419, -1923, -2179, -891, -1919, -2535
Offset: 0

Views

Author

Paul Barry, Apr 14 2005

Keywords

Comments

Conjecture : a(2n)=1 mod 4 for all n, a(2n+1)=0 for all n.

Crossrefs

Programs

A105594 Triangle read by rows: abs(A103447)*A047999 mod 2.

Original entry on oeis.org

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

Views

Author

Paul Barry, Apr 14 2005

Keywords

Comments

Row sums are A105595.

Examples

			Triangle starts
1;
0,1;
1,1,1;
0,0,0,1;
1,0,1,0,1;
0,1,0,1,0,1;
0,0,0,0,1,1,1;
		

Crossrefs

Programs

  • Maple
    A105594 := proc(n,k)
        add( abs(numtheory[mobius](binomial(n,j)))*modp(binomial(j,k),2) ,j=0..n) ;
        % mod 2 ;
    end proc: # R. J. Mathar, Nov 28 2014
  • Mathematica
    T[n_, k_] := Sum[Abs[MoebiusMu[Binomial[n, j]]*Mod[Binomial[j, k], 2]], {j, 0, n}] // Mod[#, 2]&;
    Table[T[n, k], {n, 0, 13}, {k, 0, n}] // Flatten (* Jean-François Alcover, Jan 15 2020 *)

Formula

T(n, k) = mod(Sum_{j=0..n}(abs(mu(binomial(n,j)))*mod(binomial(j,k),2)), 2).

A105597 Central numbers in a Moebius-binomial triangle.

Original entry on oeis.org

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

Views

Author

Paul Barry, Apr 14 2005

Keywords

Comments

Central numbers in A105595.
There seems to be a typo in above comment, maybe A105594 was intended? - Antti Karttunen, Aug 27 2017
Partial sums are A105598.

Programs

  • Mathematica
    a[n_]:= Binomial[Abs[MoebiusMu[n]],Abs[MoebiusMu[Floor[n/2]]]];Table[a[n],{n,0,100}] (* James C. McMahon, Jan 23 2024 *)
  • PARI
    A105597(n) = if(n<2,1,binomial(abs(moebius(n)), abs(moebius(n\2)))); \\ Antti Karttunen, Aug 27 2017

Formula

a(n) = binomial(abs(mu(n)), abs(mu(floor(n/2)))).
Showing 1-3 of 3 results.