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A264841 Triangle read by rows: T(n,k) is the number of ways to partition an n X k square grid into any number of parts along the gridlines. 1

%I #23 Feb 25 2016 03:13:28

%S 1,2,12,4,74,1442,8,456,28028,1716098,16,2810,544844,105093828,

%T 20276816980,32,17316,10591310,6435880414,3912156203494,

%U 2378025136264102,64,106706,205886234,394129505248,754801786191820,1445496758320387318,2768227968406304217000,128,657552,4002256640,24136256828880

%N Triangle read by rows: T(n,k) is the number of ways to partition an n X k square grid into any number of parts along the gridlines.

%C A set of edges forms a valid partition if and only if it includes the entire boundary of the grid, and there are no vertices of degree 1.

%H Danny Rorabaugh, <a href="/A264841/a264841.pdf">A264841 Example: T(2,2)</a>

%H R. J. Mathar, <a href="http://www.vixra.org/abs/1511.0225">Counting 2-way monotonic terrace forms over rectangular landscapes</a>, see Section 6.3, Combinatorics and Graph Theory, viXra:1511.0225, 2015.

%F T(n,1) = 2^(n-1).

%F T(n,2) = A078469(n).

%e The triangle T(n,k) begins:

%e n\k 1 2 3 4 5

%e 1: 1

%e 2: 2 12

%e 3: 4 74 1442

%e 4: 8 456 28028 1716098

%e 5: 16 2810 544844 105093828 20276816980

%Y A078469 is the second column of this triangle.

%K nonn,tabl

%O 1,2

%A _Linus Hamilton_, Nov 26 2015

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Last modified April 25 01:35 EDT 2024. Contains 371964 sequences. (Running on oeis4.)