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A250907 Number of (n+1) X (2+1) 0..2 arrays with no 2 X 2 subblock having its maximum diagonal element less than its minimum antidiagonal element. 1

%I

%S 603,13401,297873,6621219,147178899,3271547025,72721157625,

%T 1616472795339,35931555318411,798699904707465,17753796965556513,

%U 394637967071813043,8772158730705164739,194990789577739653441,4334327408721425197833

%N Number of (n+1) X (2+1) 0..2 arrays with no 2 X 2 subblock having its maximum diagonal element less than its minimum antidiagonal element.

%H R. H. Hardin, <a href="/A250907/b250907.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 24*a(n-1) - 41*a(n-2) + 36*a(n-3).

%F Empirical g.f.: 9*x*(67 - 119*x + 108*x^2) / (1 - 24*x + 41*x^2 - 36*x^3). - _Colin Barker_, Nov 23 2018

%e Some solutions for n=2:

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

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

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

%Y Column 2 of A250913.

%K nonn

%O 1,1

%A _R. H. Hardin_, Nov 28 2014

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Last modified April 1 19:13 EDT 2023. Contains 361695 sequences. (Running on oeis4.)