A319283 - OEIS

%I #9 Sep 18 2018 02:41:31

%S 1,2,3,6,17,54,153,552,2057,8394,35539,166926,856189,4674890,27358553,

%T 171129072,1141190303,8017021932,59365844491,461939618824

%N Number of nodes of the backtrack tree for the n queens problem.

%D D. E. Knuth, The Art of Computer Programming, Volume 4, Pre-fascicle 5B, Introduction to Backtracking, 7.2.2. Backtrack programming. 2018.

%Y Row sums of A319284.

%Y Cf. A000170.

%K nonn,more

%O 0,2

%A _Peter Luschny_, Sep 16 2018