cp's OEIS Frontend

A203980 Number of (n+1) X 5 0..2 arrays with no 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order.

%I A203980 #9 Jun 06 2018 05:41:26
%S A203980 384,5184,69984,956448,13071456,178855776,2447270496,33489653472,
%T A203980 458288894304,6271519652064,85823503984224,1174465206026208,
%U A203980 16072153386090336,219941927082883296,3009830115907061856
%N A203980 Number of (n+1) X 5 0..2 arrays with no 2 X 2 subblock having equal diagonal elements or equal antidiagonal elements, and new values 0..2 introduced in row major order.
%C A203980 Column 4 of A203984.
%H A203980 R. H. Hardin, <a href="/A203980/b203980.txt">Table of n, a(n) for n = 1..210</a>
%F A203980 Empirical: a(n) = 15*a(n-1) - 270*a(n-3) + 324*a(n-4).
%F A203980 Empirical g.f.: 96*x*(4 - 6*x - 81*x^2 + 108*x^3) / ((1 - 15*x + 18*x^2)*(1 - 18*x^2)). - _Colin Barker_, Jun 06 2018
%e A203980 Some solutions for n=4:
%e A203980 ..0..1..1..2..0....0..1..1..1..1....0..1..1..1..1....0..1..2..1..2
%e A203980 ..2..2..0..2..0....2..2..2..2..0....2..2..2..2..0....2..1..2..1..2
%e A203980 ..0..1..1..2..1....1..0..0..1..1....1..0..1..1..0....0..0..2..0..2
%e A203980 ..0..2..0..2..0....2..2..2..2..2....1..0..2..2..2....2..1..1..1..1
%e A203980 ..0..1..0..1..0....0..1..0..1..0....1..0..1..0..1....0..0..0..0..2
%Y A203980 Cf. A203984.
%K A203980 nonn
%O A203980 1,1
%A A203980 _R. H. Hardin_, Jan 09 2012