A196806 - OEIS

%I #5 Mar 31 2012 12:36:27

%S 1,17,120,1515,19449,166682,1730105,18344433,186996068,1929020093,

%T 20000798340,205893266832,2122824479646,21911879424345,

%U 226005819417517,2331282643796687,24051519818547252,248109780944578426

%N Number of nX5 0..4 arrays with each element x equal to the number its horizontal and vertical neighbors equal to 4,2,3,0,1 for x=0,1,2,3,4

%C Every 0 is next to 0 4's, every 1 is next to 1 2's, every 2 is next to 2 3's, every 3 is next to 3 0's, every 4 is next to 4 1's

%C Column 5 of A196809

%H R. H. Hardin, <a href="/A196806/b196806.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 2*a(n-1) +46*a(n-2) +251*a(n-3) +912*a(n-4) +3106*a(n-5) +33732*a(n-6) +134128*a(n-7) -20034*a(n-8) -567014*a(n-9) -375318*a(n-10) -6015368*a(n-11) -16173299*a(n-12) -1856398*a(n-13) -6077492*a(n-14) +115957*a(n-15) +86716000*a(n-16) +121879353*a(n-17) +143953434*a(n-18) +89210978*a(n-19) -338982089*a(n-20) +596943388*a(n-21) -937879207*a(n-22) -29192016*a(n-23) +898444015*a(n-24) -968379863*a(n-25) +1255345857*a(n-26) -1174344242*a(n-27) +285800984*a(n-28) +142375346*a(n-29) -191125798*a(n-30) +133032528*a(n-31) -51445208*a(n-32) +22658488*a(n-33) +6236280*a(n-34) -4351872*a(n-35) +1586080*a(n-36) -1187040*a(n-37) +225696*a(n-38) +24640*a(n-39) +37248*a(n-40) +13824*a(n-41)

%e Some solutions for n=4

%e ..0..0..0..3..0....0..0..3..0..0....0..0..0..0..0....0..0..3..0..0

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

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

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

%K nonn

%O 1,2

%A _R. H. Hardin_ Oct 06 2011