%I A060870
%S A060870 4,144,3844,97344,2439844,61027344,1525839844,38146777344,953673339844,
%T A060870 23841853027344,596046423339844,14901161071777344,372529029235839844,
%U A060870 9313225743103027344,232830643638610839844,5820766091270446777344
%N A060870 Number of n X n matrices over GF(5) with rank 1.
%H A060870 Harry J. Smith, <a href="b060870.txt">Table of n, a(n) for n=1,...,200</
               a>
%F A060870 a(n) = 1/4 * (5^n - 1)^2
%e A060870 a(2) = 144 because there are 145 (the second element in sequence A060720) 
               singular 2X2 matrices over GF(5), that have rank <= 1 of which only 
               the zero matrix has rank zero so a(2) = 145 - 1 = 144.
%o A060870 (PARI) { for (n=1, 200, write("b060870.txt", n, " ", (5^n - 1)^2 / 4); 
               ) } [From Harry J. Smith (hjsmithh(AT)sbcglobal.net), Jul 13 2009]
%Y A060870 A060720.
%Y A060870 Sequence in context: A017294 A134631 A036511 this_sequence A084703 A122747 
               A069135
%Y A060870 Adjacent sequences: A060867 A060868 A060869 this_sequence A060871 A060872 
               A060873
%K A060870 nonn,easy
%O A060870 1,1
%A A060870 Ahmed Fares (ahmedfares(AT)my-deja.com), May 04 2001
%E A060870 More terms from Larry Reeves (larryr(AT)acm.org), May 07 2001