%I A073964
%S A073964 0,2,6,20,100,600,3150,15750,78000,390000
%N A073964 Number of strings of length n over Z_5 with trace 0 and subtrace 1.
%C A073964 Same as the number of strings of length n over Z_5 with trace 0 and subtrace 
               4. Same as the number of strings of length n over GF(5) with trace 
               0 and subtrace 1. Same as the number of strings of length n over 
               GF(5) with trace 0 and subtrace 4.
%H A073964 F. Ruskey, <a href="http://www.theory.csc.uvic.ca/~cos/inf/trs/str/Zq/
               str_tr_subtr_Z5.html">Strings over Z_5 of given trace and subtrace</
               a>
%H A073964 F. Ruskey, <a href="http://www.theory.csc.uvic.ca/~cos/inf/trs/str/Fq/
               str_tr_subtr_F5.html">Strings over GF(5) of given trace and subtrace</
               a>
%F A073964 a(n; t, s) = a(n-1; t, s) + a(n-1; t+4, s+4t+1) + a(n-1; t+3, s+3t+4) 
               + a(n-1; t+2, s+2t+4) + a(n-1; t+1, s+t+1)
%Y A073964 Cf. A073963, A073965, A073966, A073967, A073968, A073969, A073970.
%Y A073964 Sequence in context: A026991 A049379 A003094 this_sequence A079457 A079455 
               A052433
%Y A073964 Adjacent sequences: A073961 A073962 A073963 this_sequence A073965 A073966 
               A073967
%K A073964 easy,nonn
%O A073964 1,2
%A A073964 Frank Ruskey, Nate Kube (fruskey(AT)cs.uvic.ca), Aug 15 2002