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A143104 Infinite Redheffer matrix read by upwards antidiagonals. 18
1, 1, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1, 0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 1, 0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The determinant of the nxn Redheffer matrix is given by Mertens function A002321(n).

For n>1, replacing a(n,n) with 0 in the Redheffer matrix and taking the determinant gives moebius(n)=A008683(n). The number of permutations with non-zero contribution to this determinant is given by A002033. For first few n, these permutations are shown in the sequences A144193 to A144201. [From Mats Granvik, Sep 14 2008]

The determinant that is the Moebius function was discovered by reading the blog post "The Mobius function is strongly orthogonal to nilsequences" by Terence Tao. [From Mats Granvik, Jan 24 2009]

REFERENCES

R. M. Redheffer, Eine explizit lösbare Optimierungsaufgabe, Internat. Schiftenreihe Numer. Math., 36 (1977), 213-216.

R. C. Vaughan, On the eigenvalues of Redheffer's matrix, II, J. Austral. Math. Soc. (Series A) 60 (1996), 260-273.

R. C. Vaughan, On the eigenvalues of Redheffer’s matrix I, in : Number Theory with an Emphasis on the Markoff Spectrum (Provo, Utah, 1991), 283-296, Lecture Notes in Pure and Appl. Math.,147, Dekker, New-York, 1993.

Herbert S. Wilf, The Redheffer matrix of a partially ordered set, The Electronic Journal of Combinatorics 11(2) (2004), #R10

LINKS

Enrique Pérez Herrero, Rows n = 1..100 of triangle, flattened

Olivier Bordellès and Benoit Cloitre, A matrix inequality for Möbius functions, J. Inequal. Pure and Appl. Math., Volume 10 (2009), Issue 3, Article 62, 9 pp.

T. Tao, The Mobius function is strongly orthogonal to nilsequences

E. W. Weisstein, MathWorld: Redheffer Matrix.

Herbert S. Wilf, The Redheffer matrix of a partially ordered set, arXiv:math/0408263v1

FORMULA

a(i,j) = 1 if j=1 or j|i; 0 otherwise.

a(A000217(n))=a(A000217(n)+1)=1 [From Enrique Pérez Herrero, Apr 16 2010]

MATHEMATICA

Contribution from Enrique Pérez Herrero, Apr 13 2010: (Start)

Redheffer[i_, j_] := Boole[Divisible[i, j] || (i == 1)];

T[n_] := n*(n + 1)/2;

S[n_] := Floor[1/2 + Sqrt[2 n]];

j[n_] := 1 + T[S[n]] - n;

i[n_] := 1 + S[n] - j[n];

A143104[n_] := Redheffer[i[n], j[n]]; (End)

PROG

(Excel cell formula) =if(mod(column(); row())=0; 1; if(column()=1; 1; 0)). Produces the Redheffer matrix.

(PARI) { a(i, j) = (j==1) || (j%i==0); }

CROSSREFS

Cf. A008683, A051731.

Cf. A002033, A144193 .. A144201, A143142. [From Mats Granvik, Sep 14 2008]

Sequence in context: A014086 A014163 A166360 * A127236 A117947 A175860

Adjacent sequences:  A143101 A143102 A143103 * A143105 A143106 A143107

KEYWORD

nonn,tabl

AUTHOR

Mats Granvik, Roger L. Bagula and Gary W. Adamson, Jul 24 2008

EXTENSIONS

Edited and extended by Max Alekseyev, Oct 28 2008

STATUS

approved

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Last modified May 22 00:16 EDT 2013. Contains 225508 sequences.