A189645 - OEIS

%I #8 May 05 2014 00:42:26

%S 5,185,4277,107080,2631821,64890337,1598901325,39401919001,

%T 970964720320,23927183356745,589629702461885,14530053018698289,

%U 358059360274087325,8823540150072892232,217435624721745257829,5358195248586080351465

%N Number of n X 4 array permutations with each element moving zero or one space horizontally, diagonally or antidiagonally.

%C Column 4 of A189650.

%H R. H. Hardin, <a href="/A189645/b189645.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 30*a(n-1) -126*a(n-2) -298*a(n-3) +4076*a(n-4) -9643*a(n-5) -26*a(n-6) +67624*a(n-7) -249088*a(n-8) +187462*a(n-9) +574310*a(n-10) -970738*a(n-11) +67260*a(n-12) +489180*a(n-13) +209922*a(n-14) -640310*a(n-15) +258090*a(n-16) +58776*a(n-17) -37696*a(n-18) -25814*a(n-19) +20091*a(n-20) -3196*a(n-21) -638*a(n-22) +270*a(n-23) -30*a(n-24) +a(n-25).

%e Some solutions for 3 X 4:

%e ..0..4..5..2....5..4..7..3....0..2..1..6....0..2..1..3....5..0..3..6

%e ..1..6..3..7....1..0.11..2....5..4..3.10....9..5..7..6....1..4..7..2

%e ..8.10..9.11....8..6..9.10....8..9..7.11....8..4.11.10....9..8.11.10

%K nonn

%O 1,1

%A _R. H. Hardin_, Apr 24 2011