cp's OEIS Frontend

A195003 Number of lower triangles of a 7 X 7 0..n array with each element differing from all of its horizontal and vertical neighbors by one.

%I A195003 #9 May 06 2018 10:12:56
%S A195003 2,69632,641376,2059822,3816148,5740166,7686580,9643120,11600228,
%T A195003 13557614,15515004,17472396,19429788,21387180,23344572,25301964,
%U A195003 27259356,29216748,31174140,33131532,35088924,37046316,39003708,40961100,42918492
%N A195003 Number of lower triangles of a 7 X 7 0..n array with each element differing from all of its horizontal and vertical neighbors by one.
%C A195003 Row 7 of A194998.
%H A195003 R. H. Hardin, <a href="/A195003/b195003.txt">Table of n, a(n) for n = 1..200</a>
%F A195003 Empirical: a(n) = 1957392*n - 6016308 for n>10.
%F A195003 Empirical g.f.: 2*x*(1 + 34814*x + 251057*x^2 + 423351*x^3 + 168940*x^4 + 83846*x^5 + 11198*x^6 + 5063*x^7 + 284*x^8 + 139*x^9 + 2*x^10 + x^11) / (1 - x)^2. - _Colin Barker_, May 06 2018
%e A195003 Some solutions for n=4:
%e A195003 ..0..............0..............0..............0..............0
%e A195003 ..1.0............1.0............1.0............1.0............1.0
%e A195003 ..2.1.2..........0.1.2..........0.1.2..........2.1.2..........2.1.2
%e A195003 ..1.2.1.2........1.0.1.2........1.2.1.2........1.2.3.4........1.0.1.2
%e A195003 ..2.3.2.1.2......0.1.0.1.2......2.3.2.1.2......2.3.4.3.2......2.1.2.1.2
%e A195003 ..1.2.1.2.1.2....1.0.1.0.1.2....1.2.3.2.1.0....1.2.3.2.1.0....1.2.1.0.1.2
%e A195003 ..0.1.2.3.2.1.0..2.1.2.1.2.3.2..2.3.2.1.2.1.0..2.3.2.1.0.1.0..2.3.2.1.2.3.2
%Y A195003 Cf. A194998.
%K A195003 nonn
%O A195003 1,1
%A A195003 _R. H. Hardin_, Sep 07 2011