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A096195 a(n) = number of distinct solutions to the set of equations 1 +- x +- x^2 +- ... +- x^n = 0 over the complex numbers. 1
2, 8, 16, 64, 106, 324, 696, 1856, 4046, 10240, 19084, 49152, 98110, 218140, 464084, 1047744, 2123446, 4718592, 9632740, 20666444 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..20.

EXAMPLE

a(2) = 8 because the set of equations 1 +- x +- x^2 = 0 generates 8 distinct solutions.

MATHEMATICA

a[n_] := a[n] = Length[Union[ Flatten[x /. Table[Solve[1 + Sum[(-1)^IntegerDigits[k, 2, n + 1][[p + 1]]x^p, {p, n}] == 0], {k, 0, 2^n - 1}]]]]; Table[a[n], {n, 10}]

CROSSREFS

Cf. A036289 (total number of solutions to the equations).

Sequence in context: A100243 A026523 A066792 * A094014 A098232 A354275

Adjacent sequences:  A096192 A096193 A096194 * A096196 A096197 A096198

KEYWORD

more,nonn

AUTHOR

Josh Locker (jlocker(AT)mail.rochester.edu), Jul 26 2004

EXTENSIONS

More terms from Robert G. Wilson v and Labos Elemer, Jul 27 2004

a(17)-a(19) from Robert G. Wilson v, May 05 2013

a(20) from Robert G. Wilson v, May 05 2013

STATUS

approved

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Last modified May 24 18:53 EDT 2022. Contains 354043 sequences. (Running on oeis4.)