login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A144735 Square of triangle A054533 (matrix square), read by rows. 1
1, -2, 1, -2, -3, 4, 2, -6, 0, 4, -3, -2, -6, -6, 16, 5, 0, -9, -5, 6, 4, -5, -2, -5, -6, -11, -8, 36, 0, 8, 0, -24, 0, 0, 0, 16, 0, 6, -18, 3, -3, -24, 0, 0, 36, 7, 0, 8, 2, -34, -10, 10, -8, 10, 16 (list; table; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Row sums = A008683, mu(n).

Right border = squares of phi(n).

LINKS

Table of n, a(n) for n=1..55.

FORMULA

A054533^2, as an infinite lower triangular matrix.

T(n, k) = Sum_{s = k..n) R(n, s) * R(s, k) for n >= 1 and 1 <= k <= n, where R(n, s) = A054533(n, s) = Sum_{d | gcd(n,s)} d * mu(n/d). - Petros Hadjicostas, Jul 29 2019

EXAMPLE

First few rows of the triangle are as follows:

   1;

  -2,  1;

  -2, -3,   4;

   2, -6,   0,   4;

  -3, -2,  -6,  -6,  16;

   5,  0,  -9,  -5,   6,   4;

  -5, -2,  -5,  -6, -11,  -8, 36;

   0,  8,   0, -24,   0,   0,  0, 16;

   0,  6, -18,   3,  -3, -24,  0,  0, 36;

   7,  0,   8,   2, -34, -10, 10, -8, 10, 16;

   ...

CROSSREFS

Cf. A008683, A054533.

Sequence in context: A033787 A165073 A176846 * A304734 A202275 A030307

Adjacent sequences:  A144732 A144733 A144734 * A144736 A144737 A144738

KEYWORD

tabl,sign

AUTHOR

Gary W. Adamson, Sep 20 2008

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified November 21 22:35 EST 2019. Contains 329383 sequences. (Running on oeis4.)