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A060868 Number of n X n matrices over GF(3) with rank 1. 2
2, 32, 338, 3200, 29282, 264992, 2389298, 21516800, 193690562, 1743333152, 15690352658, 141214236800, 1270931319842, 11438391444512, 102945551698418, 926510051379200, 8338590720693122, 75047317261079072, 675425857674234578 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Harry J. Smith, Table of n, a(n) for n = 1..200

Index entries for linear recurrences with constant coefficients, signature (13,-39,27).

FORMULA

a(n) = 1/2 * (3^n - 1)^2.

G.f.: -2*x*(3*x+1) / ((x-1)*(3*x-1)*(9*x-1)). [Colin Barker, Dec 23 2012]

EXAMPLE

a(2) = 32 because there are 33 (the second element in sequence A060705) singular 2 X 2 matrices over GF(3), that have rank <= 1 of which only the zero matrix has rank zero so a(2) = 33 - 1 = 32.

PROG

(PARI) { for (n=1, 200, write("b060868.txt", n, " ", (3^n - 1)^2 / 2); ) } \\ Harry J. Smith, Jul 13 2009

CROSSREFS

Cf. A060705, A060867, A060869.

Sequence in context: A224293 A053065 A091707 * A270445 A199019 A127697

Adjacent sequences:  A060865 A060866 A060867 * A060869 A060870 A060871

KEYWORD

nonn,easy

AUTHOR

Ahmed Fares (ahmedfares(AT)my-deja.com), May 04 2001

EXTENSIONS

More terms from Jason Earls (zevi_35711(AT)yahoo.com), May 05 2001

STATUS

approved

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Last modified September 20 12:42 EDT 2017. Contains 292271 sequences.