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A115491 Number of monic irreducible polynomials of degree 5 in GF(2^n)[x]. 1
6, 204, 6552, 209712, 6710880, 214748352, 6871947648, 219902325504, 7036874417664, 225179981368320, 7205759403792384, 230584300921368576, 7378697629483819008, 236118324143482257408, 7555786372591432335360 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 1..670

Max Alekseyev, Formula for the number of monic irreducible polynomials in a finite field

Max Alekseyev, PARI scripts for various problems

Index entries for linear recurrences with constant coefficients, signature (34,-64).

FORMULA

a(0)=0, a(1)=6; for n>1, a(n)=34*a(n-1)-64*a(n-2). - T. D. Noe, Nov 30 2006

a(n) = (32^n-2^n)/5. - Paolo P. Lava, Jun 17 2008, adapted to the offset by Vincenzo Librandi, Jul 25 2014 and simplified by R. J. Mathar, Jul 25 2014

G.f.: 6*x / ( (32*x-1)*(2*x-1) ). - R. J. Mathar, Jul 23 2014

MATHEMATICA

CoefficientList[Series[6/((32 x - 1) (2 x - 1)), {x, 0, 30}], x] (* Vincenzo Librandi, Jul 25 2014 *)

PROG

(MAGMA) [(32^(n+1)-16*2^(n+1))/160: n in [1..20]]; // Vincenzo Librandi, Jul 25 2014

CROSSREFS

Cf. A115457-A115505.

Sequence in context: A274481 A256799 A003743 * A082405 A183595 A054653

Adjacent sequences:  A115488 A115489 A115490 * A115492 A115493 A115494

KEYWORD

nonn,easy

AUTHOR

Max Alekseyev, Jan 16 2006

STATUS

approved

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Last modified August 5 21:18 EDT 2020. Contains 336213 sequences. (Running on oeis4.)