A235317 - OEIS

%I #7 Jun 18 2022 23:04:10

%S 41216,71896,118160,241600,459536,1062832,2291696,5805424,13828496,

%T 37480816,96320240,274905520,748476176,2225038192,6336650096,

%U 19467254704,57471337616,181369764976,551385678320,1778749067440,5539587136016

%N Number of (n+1) X (6+1) 0..6 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 7 (constant-stress 1 X 1 tilings).

%C Column 6 of A235319

%H R. H. Hardin, <a href="/A235317/b235317.txt">Table of n, a(n) for n = 1..68</a>

%F Empirical: a(n) = 4*a(n-1) +47*a(n-2) -200*a(n-3) -901*a(n-4) +4204*a(n-5) +8957*a(n-6) -48440*a(n-7) -47194*a(n-8) +334096*a(n-9) +101948*a(n-10) -1410080*a(n-11) +170136*a(n-12) +3549696*a(n-13) -1446912*a(n-14) -4861440*a(n-15) +2954880*a(n-16) +2764800*a(n-17) -2073600*a(n-18).

%e Some solutions for n=3:

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

%e   3 0 3 0 5 0 4      4 6 3 6 3 6 2      5 2 5 4 5 4 5

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 05 2014