A110032 - OEIS

A110032

A characteristic triangle for the Euler totient function (A000010).

1, -1, 1, 1, -3, 1, 0, 5, -7, 1, -4, 22, 23, -13, 1, -64, 20, 172, 29, -19, 1, -240, -1120, -496, 354, 111, -29, 1, 2656, 1760, -4952, -1816, 1054, 239, -41, 1, 15360, 24800, -28640, -29040, 2384, 3938, 203, -49, 1, 88064, 587136, 601216, -63776, -191224, -21360, 6658, 511, -65, 1, -1714176, -4244224, 4907392

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OFFSET

0,5

COMMENTS

Form the n X n Hankel matrices phi(i-j+1), 1<=i,j<=n for the Euler totient function and take characteristic polynomials. Triangle rows give coefficients of the characteristic polynomials of these matrices. (Construction described by Michael Somos in A064831). First column is a signed version of Hankel transform of Euler totient function, A056229.

LINKS

Table of n, a(n) for n=0..57.

EXAMPLE

Rows begin

-1,1;

1,-3,1;

0,5,-7,1;

-4,22,23,-13,1;

-64,20,172,29,-19,1;

-240,-1120,-496,354,111,-29,1;

CROSSREFS

Sequence in context: A362885 A227342 A329989 * A201667 A175779 A280819

Adjacent sequences: A110029 A110030 A110031 * A110033 A110034 A110035

KEYWORD

sign,tabl

AUTHOR

Paul Barry, Jul 08 2005

STATUS

approved