

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
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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) / ((x1)*(3*x1)*(9*x1)). [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: A053065 A091707 A323639 * A270445 A199019 A127697
Adjacent sequences: A060865 A060866 A060867 * A060869 A060870 A060871


KEYWORD

nonn,easy


AUTHOR

Ahmed Fares (ahmedfares(AT)mydeja.com), May 04 2001


EXTENSIONS

More terms from Jason Earls, May 05 2001


STATUS

approved



