login
A140324
A new way to compute polynomial triangles from matrices of a Folium Implicit type: M={{0, -w[1], -w[2]}, {w[1], 0, -w[1]}, {w[2], w[1], 0}} that gives even only monomials as w[1]=x, others as one.
0
1, 0, 0, 1, 1, -2, -1, 2, 1, 1, -8, 22, -22, 1, 6, 1, 0, 0, 9, -54, 117, -102, 18, 12, 1, 1, -6, 3, 48, -101, -32, 291, -294, 70, 20, 1
OFFSET
1,6
COMMENTS
Matrix of the type
{{x,y,a},
{y,a,x},
{a,x,y}}
gives the folium of Descartes implicit polynomial:
x^3+y^3+a^3-3a*x*y
These types of polynomials gives various types of implicit curves in higher dimensions.
Unsigned version of this sequence algorithm gives A055137.
Some of these polynomials are similar to the Hodge number / diamond type Calabi-Yau implicit or Algebraic varieties. Here I have invented a way to make monomials from the higher polynomials. In the past I have used this matrix method to produce 3d Implicit surfaces.
FORMULA
Compute matrices as: T(n,m)=Sign[n - m]*w[Abs[n - m]]; Change to monomial as:If[n==1,w[n]=x,w[n]=1]; Take determinant of matrices M(d); out_n,m=Coefficients(Det(M(d)))).
EXAMPLE
{1},
{},
{0, 0, 1},
{},
{1, -2, -1, 2, 1},
{},
{1, -8, 22, -22, 1, 6, 1},
{},
{0, 0, 9, -54, 117, -102, 18, 12, 1},
{},
{1, -6, 3, 48, -101, -32, 291, -294, 70, 20, 1}
MATHEMATICA
Clear[M, a, d, x, w] M[d_] := Table[Sign[n - m]*w[Abs[n - m]], {n, 1, d}, {m, 1, d}]; a = Table[M[d], {d, 1, 10}]; Table[If[n == 1, w[n] = x, w[n] = 1], {n, 0, 10}]; Table[Det[a[[d]]], {d, 1, 10}]; a0 = Join[{{1}}, Table[CoefficientList[Det[a[[d]]], x], {d, 1, 10}]]; Flatten[a0] Table[Apply[Plus, CoefficientList[Det[a[[d]]], x]], {d, 1, 10}]
CROSSREFS
Sequence in context: A079900 A188317 A117354 * A323284 A010250 A268041
KEYWORD
uned,tabf,sign
AUTHOR
STATUS
approved