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A114798 Cubic polynomial coefficients such that an elliptical term is zero. +0
1
3, 2, 12, 16, 27, 54, 48, 128, 75, 250, 108, 432, 147, 686, 192, 1024, 243, 1458, 300, 2000, 363, 2662, 432, 3456, 507, 4394, 588, 5488, 675, 6750, 768, 8192, 867, 9826, 972, 11664, 1083, 13718, 1200, 16000, 1323, 18522, 1452, 21296, 1587, 24334, 1728 (list; graph; listen)
OFFSET

0,1

COMMENT

I had noticed that the elliptical term: j=g2[n]^3/(g2[n]^2-27*g3[n]^2) was singular for a kind of polynomial with three real roots: (x+n)^2*(x-2*n) This table gives all zeros: Table[((4*a[[2*n + 1]])^3 - 27*(4*a[[2*n + 2]])^2)/(4*a[[2*n + 1]])^3, {n, 0, 49}]

FORMULA

w^2=4*z^3-g2[n]*z-g3[n] a(n) = {g2[n],g3[n]}/4

EXAMPLE

x^3-3*x-2

x^3-12*x-16

x^3-27*x-54

MATHEMATICA

a = Flatten[Table[Abs[Coefficient[Expand[(x + n)^2*(x - 2*n)], x, 1 - m]], {n, 1, 50}, {m, 0, 1}]]

CROSSREFS

Sequence in context: A129925 A057779 A005220 this_sequence A113205 A136657 A006774

Adjacent sequences: A114795 A114796 A114797 this_sequence A114799 A114800 A114801

KEYWORD

nonn,uned

AUTHOR

Roger Bagula (rlbagulatftn(AT)yahoo.com), Feb 18 2006

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Last modified November 18 20:14 EST 2008. Contains 147244 sequences.


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