OFFSET
1,1
LINKS
Alois P. Heinz, Table of n, a(n) for n = 1..70
Eric Weisstein's World of Mathematics, Cycle Graph
Eric Weisstein's World of Mathematics, Path Graph
Eric Weisstein's World of Mathematics, Spanning Tree
FORMULA
See program.
MAPLE
a:= n-> 9* (Matrix([[0, 1, 265, 50616, 9209545, 1658090689, 297747101520, 53431400864569, 9586723471888105][1+abs(i)]$i=-7..8]). Matrix(16, (i, j)-> if i=j-1 then 1 elif j=1 then [[-427427424, 327381265, -146975161, 38357160, -5699687, 457655, -17736, 265, -1][1+abs(k)]$k=-7..8][i] else 0 fi)^n)[1, 8]^2: seq(a(n), n=1..20);
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Alois P. Heinz, Nov 26 2010
STATUS
approved