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A139813
A polynomial triangle based on cross binomial Hodge number matrices/ Hodge diamonds that represent Calabi-Yau type binomials and their monomials.
1
1, 2, 2, 2, 2, 2, 2, 6, 6, 2, 2, 8, 6, 8, 2, 2, 10, 20, 20, 10, 2, 2, 12, 30, 20, 30, 12, 2, 2, 14, 42, 70, 70, 42, 14, 2, 2, 16, 56, 112, 70, 112, 56, 16, 2, 2, 18, 72, 168, 252, 252, 168, 72, 18, 2, 2, 20, 90, 240, 420, 252, 420, 240, 90, 20, 2
OFFSET
1,2
COMMENTS
The matrices M(n X n): crossed Pascal matrices:
{{1}}
---
{{1,1},
{1,1}}
---
{{1,0,1},
{0,2,0},
{1,0,1}}
---
{{1,0,0,1},
{0,3,3,0}.
{0,3,3,0},
{1,0,0,1}}
---
{{1,0,0,0,1},
{0,4,0,4.0},
{0,0,6,0,0},
{0,4,0,4.0},
{1,0,0,0,1}}
---
{{1,0,0,0,01},
{0,5,0,0,5.0},
{0,0,10,10,0,0},
{0,0,10,10,0,0},
{0,5,0,0,5.0},
{1,0,0,0,01}}
Row sums: {1, 4, 6, 16, 26, 64, 108, 256, 442, 1024, 1796, ...}.
Fourier-like visualization of the polynomials:
s = Table[ParametricPlot3D[{g[[n]] /. x -> Cos[t], g[[
n]] /. x -> Sin[t], n3}, {t, -Pi, Pi}], {n, 1, 10}];
Show[s, PlotRange -> All]
These are Calabi-Yau type n-fold manifolds as Hodge monomial polynomials.
The K3 Hodge number matrix/ diamond is ( 2+20*x+23*x^2 ): M is
{{1,0,1},
{0,20,0},
{1,0,1}}
That matrix is this M[3] matrix 3X3 with the central 2 multiplied by a constant 10.
This kind of polynomial has been a staple of Calabi-Yau Algebraic Geometry of varieties since the early 90's.
The highest n-fold Hodge diamond matrices that I found in the literature that gave me this idea was by Rolf Schimrigk (see links).
REFERENCES
Christian Meyer, Modular Calabi-Yau threefolds, 2005.
FORMULA
Matrices: T(n,m,d)= If[n - m == 0, Binomial[d, n], If[d - n - m == 0, Binomial[d, m], 0]]; T(n,m,d)->Matrix M(d]); Polynomials in two variables: p(x,y,d)=Sum[Sum[M[d][[k, m]]*x^(k - 1)*y^(m - 1), {m, 1, d + 1}], {k, 1, d + 1}]; Sequence is: a(n,m)_out=Coefficients(p(x,1,d)).
EXAMPLE
{1},
{2, 2},
{2, 2, 2},
{2, 6, 6, 2},
{2, 8, 6, 8, 2},
{2, 10, 20, 20, 10, 2},
{2, 12, 30, 20, 30, 12, 2},
{2, 14, 42, 70, 70, 42, 14, 2},
{2, 16, 56, 112, 70, 112, 56, 16, 2},
{2, 18, 72, 168, 252, 252, 168, 72, 18, 2},
{2, 20, 90, 240, 420, 252, 420, 240, 90, 20, 2}
MATHEMATICA
Clear[T, M, p, a, g] T[n_, m_, d_] := If[n - m == 0, Binomial[d, n], If[d - n - m == 0, Binomial[d, m], 0]]; M[d_] := Table[T[n, m, d], {n, 0, d}, {m, 0, d}]; p[x_, y_, d_] := Sum[Sum[M[d][[k, m]]*x^(k - 1)*y^(m - 1), {m, 1, d + 1}], {k, 1, d + 1}]; g = Table[ExpandAll[p[x, 1, d]], {d, 1, 10}]; a = Join[{{1}}, Table[CoefficientList[p[x, 1, w], x], {w, 1, 10}]]; Flatten[a] Join[{1}, Table[Apply[Plus, CoefficientList[p[x, 1, w], x]], {w, 1, 10}]];
CROSSREFS
Sequence in context: A105255 A351023 A140818 * A172009 A299150 A202448
KEYWORD
nonn,tabl,uned
AUTHOR
STATUS
approved