

A060871


Number of n X n matrices over GF(7) with rank 1.


1



6, 384, 19494, 960000, 47073606, 2306841984, 113036904294, 5538819840000, 271402252867206, 13298710955443584, 651636840771389094, 31930205225480640000, 1564580056242329380806, 76664422757230585805184
(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 (57,399,343).


FORMULA

a(n) = 1/6 * (7^n  1)^2.
G.f.: 6*x*(7*x+1) / ((x1)*(7*x1)*(49*x1)). [Colin Barker, Dec 23 2012]


EXAMPLE

a(2) = 384 because there are 385 (the second element in sequence A060721) singular 2 X 2 matrices over GF(7), that have rank <= 1 of which only the zero matrix has rank zero so a(2) = 385  1 = 384.


PROG

(PARI) { for (n=1, 200, write("b060871.txt", n, " ", (7^n  1)^2 / 6); ) } \\ Harry J. Smith, Jul 13 2009


CROSSREFS

Cf. A060721.
Sequence in context: A245398 A078207 A261296 * A193133 A162137 A119645
Adjacent sequences: A060868 A060869 A060870 * A060872 A060873 A060874


KEYWORD

nonn,easy


AUTHOR

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


EXTENSIONS

More terms from Larry Reeves (larryr(AT)acm.org), May 07 2001


STATUS

approved



