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A158452 A triangle sequence of permutation Hadamard {1,-1) matrix polynomials: M(d)=Table[If[ m == n, d!/n!, 0], {n, d}, {m, d}]; m(n)=M(2^n)*Hadamard(2^n) 0

%I #2 Mar 30 2012 17:34:35

%S 1,2,2,1,-1,24,24,24,24,12,-12,12,-12,4,-4,-4,4,1,1,-1,-1,40320,40320,

%T 40320,40320,40320,40320,40320,40320,20160,-20160,-20160,-20160,20160,

%U 20160,-20160,20160,6720,6720,-6720,-6720,-6720,-6720,6720,6720,1680

%N A triangle sequence of permutation Hadamard {1,-1) matrix polynomials: M(d)=Table[If[ m == n, d!/n!, 0], {n, d}, {m, d}]; m(n)=M(2^n)*Hadamard(2^n)

%C Row sums are:

%C {0, -4, -25078, -6495526469206231383391390,

%C 286062680268501848545408513842882834075841335269461890307160415945609971775008

%C 5331640349522681828065666242531221092072696301456782016,...}.

%C Example matrix:

%C m(2^2)={{24, 24, 24, 24},

%C {12, -12, 12, -12},

%C {4, -4, -4, 4},

%C {1, 1, -1, -1}}.

%F M(d)=Table[If[ m == n, d!/n!, 0], {n, d}, {m, d}];

%F m(n)=M(2^n)*Hadamard(2^n);

%F out_(n,m)=coefficients(characteristicpolynomial(m(n),x),x)

%e {1, -1},

%e {-4, -1, 1},

%e {-18432, -5952, -688, -7, 1},

%t Needs["Hadamard`"];

%t M[d_] := Table[If[ m == n, d!/n!, 0], {n, d}, {m, d}];

%t a = Join[{{{1}}}, Table[M[2^n].If[Hadamard[2^n] == {} && 2^n >= 3, 0, If[2^n == 2, Hadamard[2], Hadamard[2^n][[1]]]], {n, 1, 4}]];

%t Table[CoefficientList[CharacteristicPolynomial[a[[n]], x], x], {n, 1, Length[ a]}];

%t Flatten[a]

%t Table[Apply[Plus, CoefficientList[CharacteristicPolynomial[a[[n]], x], x]], {n, 1, Length[a]}];

%K sign,tabl,uned

%O 0,2

%A _Roger L. Bagula_, Mar 19 2009

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Last modified April 19 16:03 EDT 2024. Contains 371794 sequences. (Running on oeis4.)