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 A269133 Number of ways to place m nonattacking queens on an m X n board, 1 <= m <= n (triangular array). 1

%I

%S 1,2,0,3,2,0,4,6,4,2,5,12,14,12,10,6,20,36,46,40,4,7,30,76,140,164,94,

%T 40,8,42,140,344,568,550,312,92,9,56,234,732,1614,2292,2038,1066,352,

%U 10,72,364,1400,3916,7552,9632,7828,4040,724,11,90,536,2468,8492,21362,37248,44148,34774,15116,2680,12,110,756,4080,16852,52856,120104,195270,222720,160964,68264,14200

%N Number of ways to place m nonattacking queens on an m X n board, 1 <= m <= n (triangular array).

%H Math StackExchange, <a href="http://math.stackexchange.com/questions/1657276/">State space for eight queen problem</a>

%H Marko Riedel, <a href="/A269133/a269133.pl.txt">Perl program to compute triangular array of nonattacking queens configurations</a>

%e The triangular array begins:

%e n\m 1 2 3 4 5 6 7 8 9 10 11 12

%e 1 1

%e 2 2 0

%e 3 3 2 0

%e 4 4 6 4 2

%e 5 5 12 14 12 10

%e 6 6 20 36 46 40 4

%e 7 7 30 76 140 164 94 40

%e 8 8 42 140 344 568 550 312 92

%e 9 9 56 234 732 1614 2292 2038 1066 352

%e 10 10 72 364 1400 3916 7552 9632 7828 4040 724

%e 11 11 90 536 2468 8492 21362 37248 44148 34774 15116 2680

%e 12 12 110 756 4080 16852 52856 120104 195270 222720 160964 68264 14200

%e ...

%Y Cf. A000170 (m=n).

%Y Cf. A000027 (m=1), A002378 (m=2), A061989 (m=3), A061990 (m=4), A061991 (m=5), A061992 (m=6), A061993 (m=7), A172449 (m=8).

%K nonn,tabl

%O 1,2

%A _Marko Riedel_, Feb 19 2016

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Last modified February 23 18:54 EST 2019. Contains 320438 sequences. (Running on oeis4.)