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A139146 Interpolation one-half polynomials based on Chebyshev T(x.n) polynomial coefficients(A053120 ): even-> 2*T(x,n); odd->T(x,n) + T(x,n+1). 0

%I #5 Jan 16 2022 23:07:06

%S 2,1,1,0,2,-1,1,2,-2,0,4,-1,-3,2,4,0,-6,0,8,1,-3,-8,4,8,2,0,-16,0,16,

%T 1,5,-8,-20,8,16,0,10,0,-40,0,32

%N Interpolation one-half polynomials based on Chebyshev T(x.n) polynomial coefficients(A053120 ): even-> 2*T(x,n); odd->T(x,n) + T(x,n+1).

%C Row sums are all 2.

%C The rationale behind this interpolation is that Bessel functions have 1/2 values, so what about other orthogonal polynomials?

%C The integration shows that they are "mostly" orthogonal when three away from the diagonal.

%C TableForm[Table[Integrate[p[x, m]*p[x, n]/Sqrt[1 - x^2], {x, -1, 1}], {n, 0, 10}, {m, 0, 10}]]

%C These polynomials would also be related to two-dimensional Chladni-Chebyshev type standing waves as:

%C Chladni[x,y,n,m]=ChebyshevT[n, x] + ChebyshevT[m, y].

%F even->p(x.m)= 2*T(x,n); odd->p(x,m)=T(x,n)+T(x,n+1); out_n,m=Coefficients(p(x,m).

%e {2},

%e {1, 1},

%e {0, 2},

%e {-1, 1, 2},

%e {-2, 0, 4},

%e {-1, -3, 2, 4},

%e {0, -6, 0, 8},

%e {1, -3, -8, 4,8},

%e {2, 0, -16, 0, 16},

%e {1, 5, -8, -20, 8, 16},

%e {0, 10, 0, -40, 0, 32}

%t Clear[p, x] p[x, 0] = 2*ChebyshevT[0, x]; p[x, 1] = ChebyshevT[0, x] + ChebyshevT[1, x]; p[x, 2] = 2*ChebyshevT[1, x]; p[x_, m_] := p[x, m] = If[Mod[m, 2] == 0, 2*ChebyshevT[Floor[m/2], x], ChebyshevT[Floor[m/2], x] + ChebyshevT[Floor[m/2 + 1], x]]; Table[ExpandAll[p[x, n]], {n, 0, 10}]; a = Table[CoefficientList[p[x, n], x], {n, 0, 10}]; Flatten[a] Table[Apply[Plus, CoefficientList[p[x, n], x]], {n, 0, 10}]

%Y Cf. A053120.

%K uned,tabf,sign

%O 1,1

%A _Roger L. Bagula_, Jun 05 2008

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