A112459 Absolute value of coefficient of term [x^(n-3)] in characteristic polynomial of maximum matrix A of size n X n, where n >= 3. Maximum matrix A(i,j) is MAX(i,j), where indices i and j run from 1 to n.

3, 23, 98, 308, 798, 1806, 3696, 6996, 12441, 21021, 34034, 53144, 80444, 118524, 170544, 240312, 332367, 452067

Offset

3,1

Links

Table of n, a(n) for n=3..20.

Formula

a(n) = n*(n^2-4)*(n^2-1)*(5*n+3)/6!.

G.f.: x^3*(3+2*x)/(1-x)^7. - Colin Barker, Mar 28 2012

Prog

(Octave, MATLAB) for n=3:20 a = zeros(n); for i=1:n for j=1:n a(i, j) = max(i, j); end end b = poly(a); b(4) end

Crossrefs

Cf. A000217, A000914, A001844, A112460, A112461, A112462, A112463, A112464.

Sequence in context: A196318 A213846 A301580 * A197303 A039506 A196970

Adjacent sequences: A112456 A112457 A112458 * A112460 A112461 A112462

Keyword

easy,nonn

Author

Paul Max Payton, Sep 23 2005

Extensions

Offset changed from 1 to 3 and formulas adapted by Bruno Berselli, Mar 29 2012

Status

approved