%I #16 May 02 2019 16:18:57

%S 0,0,3,24,210,1620,9072,46656,262440,1594080,9843120,60466176,

%T 367960320,2210794560,13162730688,78328332288,468205557120,

%U 2810089946880,16894457846784,101559956668416,609954817881600,3659790885120000,21947909832446976,131621703842267136

%N Number of strings of length n over Z_6 with trace 1 and subtrace 1.

%C Same as the number of strings of length n over Z_6 with trace 5 and subtrace 1.

%H Max Alekseyev, <a href="http://home.gwu.edu/~maxal/gpscripts/">PARI/GP scripts for miscellaneous math problems</a>

%H F. Ruskey <a href="http://combos.org/TSstringZ6">Strings over Z_6 with given trace and subtrace</a>

%F a(n; t, s) = a(n-1; t, s) + a(n-1; t+5, s+5t+1) + a(n-1; t+4, s+4t+4) + a(n-1; t+3, s+3t+3) + a(n-1; t+2, s+2t+2) + a(n-1; t+1, s+t+1) where t is the trace and s is the subtrace.

%Y Cf. A073971, A073972, A073973, A073974, A073975, A073976, A073977, A073979, A073980, A073981, A073982, A073983, A073984, A073985, A073986, A073987, A073988, A073989, A073990, A073991, A073992, A073993, A073994.

%K easy,nonn

%O 1,3

%A _Frank Ruskey_ and Nate Kube, Aug 16 2002

%E Terms a(11) onward from _Max Alekseyev_, Apr 09 2013