A235252 - OEIS

%I #7 Jun 18 2022 23:51:50

%S 744,2592,8328,30300,102000,382036,1330480,5080484,18163048,70306060,

%T 256589296,1003233148,3722094784,14665343468,55134285800,218558955780,

%U 830555412752,3308709067460,12685331083184,50741901100676

%N Number of (n+1) X (2+1) 0..7 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 7, with no adjacent elements equal (constant-stress tilted 1 X 1 tilings).

%C Column 2 of A235258.

%H R. H. Hardin, <a href="/A235252/b235252.txt">Table of n, a(n) for n = 1..210</a>

%F Empirical: a(n) = 6*a(n-1) +95*a(n-2) -616*a(n-3) -3917*a(n-4) +28162*a(n-5) +91198*a(n-6) -756656*a(n-7) -1296093*a(n-8) +13282950*a(n-9) +11064161*a(n-10) -160306388*a(n-11) -45638472*a(n-12) +1364159736*a(n-13) -85868097*a(n-14) -8277407564*a(n-15) +2248525953*a(n-16) +35930764870*a(n-17) -13377839510*a(n-18) -111621640828*a(n-19) +42805415777*a(n-20) +248607718870*a(n-21) -80775638437*a(n-22) -398463896692*a(n-23) +90040174737*a(n-24) +459694923182*a(n-25) -53415557378*a(n-26) -380977947608*a(n-27) +5163558960*a(n-28) +225617403088*a(n-29) +16935519648*a(n-30) -94279251328*a(n-31) -14034380336*a(n-32) +27080927712*a(n-33) +5672434272*a(n-34) -5079024000*a(n-35) -1315882368*a(n-36) +559194624*a(n-37) +167643648*a(n-38) -27371520*a(n-39) -9123840*a(n-40).

%e Some solutions for n=4:

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

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

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

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

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

%K nonn

%O 1,1

%A _R. H. Hardin_, Jan 05 2014