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A186861 Array read by antidiagonals: T(n,k) is the number of n-step king's tours on a k X k board summed over all starting positions. 8

%I #23 Dec 18 2023 11:20:40

%S 1,4,0,9,12,0,16,40,24,0,25,84,160,24,0,36,144,408,496,0,0,49,220,768,

%T 1764,1208,0,0,64,312,1240,3768,6712,2240,0,0,81,420,1824,6508,17280,

%U 22672,2984,0,0,100,544,2520,9984,32520,74072,68272,2384,0,0,121,684

%N Array read by antidiagonals: T(n,k) is the number of n-step king's tours on a k X k board summed over all starting positions.

%C Table starts

%C 1 4 9 16 25 36 49 64 81 100

%C 0 12 40 84 144 220 312 420 544 684

%C 0 24 160 408 768 1240 1824 2520 3328 4248

%C 0 24 496 1764 3768 6508 9984 14196 19144 24828

%C 0 0 1208 6712 17280 32520 52432 77016 106272 140200

%C 0 0 2240 22672 74072 156484 268048 408764 578632 777652

%C 0 0 2984 68272 296360 722384 1335984 2129440 3102752 4255920

%C 0 0 2384 183472 1110000 3193800 6481216 10899404 16418600 23038804

%C 0 0 784 436984 3908376 13530576 30543072 54738536 85743256

%C 0 0 0 905776 12956800 55056168 139775784

%H R. H. Hardin, <a href="/A186861/b186861.txt">Table of n, a(n) for n = 1..145</a>

%F Empirical, for all rows: a(n) = 3*a(n-1) - 3*a(n-2) + a(n-3) for n > 3,3,3,5,6,7,8,9 respectively for row=1..8.

%e Some n=3 solutions for 3 X 3:

%e 3 2 0 0 0 0 0 3 0 0 0 0 0 0 0 0 0 1 0 1 0

%e 1 0 0 1 0 0 0 2 0 1 2 0 2 3 0 0 2 0 2 0 0

%e 0 0 0 2 3 0 0 0 1 3 0 0 0 1 0 0 0 3 0 3 0

%Y Rows are A000290, A033586(n-1), A186862, A186863, A186864, A186865, A186866, A186867, A366829.

%K nonn,tabl

%O 1,2

%A _R. H. Hardin_, Feb 27 2011

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Last modified April 23 05:09 EDT 2024. Contains 371906 sequences. (Running on oeis4.)