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%I #13 Apr 19 2022 07:38:25
%S 0,0,2304,156672,2169600,15220800,72182880,264520704,806827392,
%T 2144534400,5120913600,11222069760
%N Number of 7-turn rook's tours on an n X n board summed over all starting positions.
%F Empirical G.f.: -96*x^3*(287*x^5+4491*x^4+11886*x^3+8776*x^2+1416*x+24)/(x-1)^9. [_Colin Barker_, Jul 01 2012]
%e Some solutions for 3X3
%e ..2..1..0....1..2..0....0..2..1....0..0..4....5..4..0....4..3..5....4..1..5
%e ..3..6..7....6..0..7....5..3..4....1..2..3....6..0..7....7..1..6....0..7..6
%e ..4..5..0....5..3..4....6..0..7....7..6..5....2..3..1....0..2..0....3..2..0
%Y Row 7 of A187189.
%K nonn,more
%O 1,3
%A _R. H. Hardin_, Mar 06 2011