Free Divisors

Sekiguchi's 17 Free Divisors

F_a1 (aka Swallowtail)
16x4z-4x3y2-128x2z2+144xy2z-27y4+256z3
F_b7
xy4-4x2y2z-2y3z+4x3z2+4xyz2+2z3
F_h7
xy3z+y5+z3
F_h3
8x3y4 +108y5 -36xy3z-x2yz2+4z3
F_h5
x3y4 -y5+3xy3z+z3
F_b5
xy4+y3z+z3
F_h1
-100z3 +8x5z2-100x2yz2+8x7yz+120x4y2z+450xy3 z-135y5-230x3 y4-20x6y3-8x9y2
F_b2
z(-2y3+4x3z+18xyz+27z2)
F_b3
z(-2y3+9xyz+45z2)
F_b4
z(9x2y2-4y3+18xyz+9z2)
F_h6
x3y4+y5-2x4y2z-4xy3z+x5z2+3x2yz2+z3
F_h2
100x3y4+y5+40x4y2z-10xy3z+ 4x5z2-15x2yz2+ z3
F_b6
9xy4+6x2y2z -4 y3z+x3z2-12xyz2+4z3
F_a2
2x6-3x4z+18x3y2-18xy2z+27y4+z3
F_h4
y5-2xy3z +x2yz2+ z3
F_b1
z(x2y2-4y3-4x3z+18xyz-27z2)
F_h8
x3y4+y5-8x4y2z-7xy3z+16x5z2+12x2yz2+z3

Various other free divisors

Normal crossings
xyz
Whitney Umbrella + adjoint plane
y(x2-y2z)
The 4 lines
xy(x+y)(x+yz)
Cusp + plane
x(y3-z2)
Cone+plane (linear free)
z(y2-xz)
Non-Pham-Brieskorn free equisingular deformation
x8+xy5+x6y2z
Simis' quintic
-x5 + 2x2y3 + xy4 + 3y5 + y4z
Damon's Hessian Deformation of x4+y4
-x4 + y4- zx2y2
Space curve disriminant
4z3+27(y2+x3+xz)2
A3 Hyperplane arrangement
(x2-y2)(x2-z2)(y2-z2)
B3 Hyperplane arrangement
xyz(x2-y2)(x2-z2)(y2-z2)
H3 Hyperplane arrangement
-xyz((b+1)x+by+z)(bx+y+(b+1)z)(x+(b+1)y+bz) ((b+1)x+by-z)(bx-y+(b+1)z)(-x+(b+1)y+bz) ((b+1)x-by+z)(-bx+y+(b+1)z)(x+(b+1)y-bz) ((b+1)x-by-z)(-bx-y+(b+1)z)(-x+(b+1)y-bz) with b=2cos(pi/5).
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