cp's OEIS Frontend

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.

%I A112459 #21 Dec 17 2017 07:58:17
%S A112459 3,23,98,308,798,1806,3696,6996,12441,21021,34034,53144,80444,118524,
%T A112459 170544,240312,332367,452067
%N 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.
%F A112459 a(n) = n*(n^2-4)*(n^2-1)*(5*n+3)/6!.
%F A112459 G.f.: x^3*(3+2*x)/(1-x)^7. - _Colin Barker_, Mar 28 2012
%o A112459 (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
%Y A112459 Cf. A000217, A000914, A001844, A112460, A112461, A112462, A112463, A112464.
%K A112459 easy,nonn
%O A112459 3,1
%A A112459 _Paul Max Payton_, Sep 23 2005
%E A112459 Offset changed from 1 to 3 and formulas adapted by _Bruno Berselli_, Mar 29 2012