A269040 - OEIS

%I #4 Feb 18 2016 09:03:46

%S 0,7128,67104,1114848,14710368,208867428,2783857776,37310632920,

%T 488972134752,6374741325108,82212554730696,1054083281172600,

%U 13425573904100400,170167484580493980,2146806101503300608

%N Number of 6Xn 0..2 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling two exactly once.

%C Row 6 of A269035.

%H R. H. Hardin, <a href="/A269040/b269040.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 12*a(n-1) +182*a(n-2) -1820*a(n-3) -15113*a(n-4) +101664*a(n-5) +646022*a(n-6) -3003324*a(n-7) -15725808*a(n-8) +55305760*a(n-9) +234926070*a(n-10) -698528578*a(n-11) -2270736611*a(n-12) +6320752450*a(n-13) +14600825558*a(n-14) -41434331996*a(n-15) -62768577651*a(n-16) +196263429930*a(n-17) +176943063476*a(n-18) -669462409316*a(n-19) -305019512324*a(n-20) +1647405492614*a(n-21) +230358934675*a(n-22) -2942270801898*a(n-23) +243588718325*a(n-24) +3841770422896*a(n-25) -923967990222*a(n-26) -3689384232910*a(n-27) +1300617284437*a(n-28) +2614259101122*a(n-29) -1127033659748*a(n-30) -1366254718948*a(n-31) +660843537364*a(n-32) +524090586634*a(n-33) -269727615782*a(n-34) -146010681184*a(n-35) +76928224259*a(n-36) +28983533038*a(n-37) -15160113967*a(n-38) -3964319226*a(n-39) +2009807783*a(n-40) +352152984*a(n-41) -170267256*a(n-42) -18138336*a(n-43) +8296524*a(n-44) +408240*a(n-45) -176400*a(n-46) for n>48

%e Some solutions for n=3

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

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

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

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

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

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

%Y Cf. A269035.

%K nonn

%O 1,2

%A _R. H. Hardin_, Feb 18 2016