A208408 - OEIS

%I #12 Oct 15 2024 15:42:03

%S 1,2,2,5,15,5,15,182,187,15,51,2698,10682,2795,51,187,41914,658450,

%T 667478,43947,187,715,658450,40883360,163422914,42012698,700075,715,

%U 2795,10370330,2540446156,40039156736,40595679634,2646531062,11188907,2795

%N T(n,k) is the number of n X k 0..3 arrays with new values 0..3 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors.

%H R. H. Hardin, <a href="/A208408/b208408.txt">Table of n, a(n) for n = 1..198</a>

%e Table starts:

%e ....1.........2..............5.................15......................51

%e ....2........15............182...............2698...................41914

%e ....5.......187..........10682.............658450................40883360

%e ...15......2795.........667478..........163422914.............40039156736

%e ...51.....43947.......42012698........40595679634..........39216100214432

%e ..187....700075.....2646531062.....10084768380770.......38410047476679936

%e ..715..11188907...166729574522...2505261257850802....37620564383817645696

%e .2795.178973355.10503950018198.622357842865595522.36847308431734650845696

%e ...

%e Some solutions for n=4 and k=3:

%e ..0..0..0....0..0..1....0..1..0....0..0..0....0..1..0....0..0..0....0..1..1

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

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

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

%Y Row 1 and column 1 are A007581(n-1).

%Y Columns 2..7 are A208402, A208403, A208404, A208405, A208406, A208407.

%Y Rows 2..7 are A208409, A208410, A208411, A208412, A208413, A208414.

%Y Main diagonal is A208401.

%K nonn,tabl

%O 1,2

%A _R. H. Hardin_, Feb 26 2012