cp's OEIS Frontend

A195002 Number of lower triangles of a 6 X 6 0..n array with each element differing from all of its horizontal and vertical neighbors by one.

%I A195002 #9 May 06 2018 10:12:47
%S A195002 2,4608,31042,81014,138956,199988,261324,322806,384292,445780,507268,
%T A195002 568756,630244,691732,753220,814708,876196,937684,999172,1060660,
%U A195002 1122148,1183636,1245124,1306612,1368100,1429588,1491076,1552564,1614052,1675540
%N A195002 Number of lower triangles of a 6 X 6 0..n array with each element differing from all of its horizontal and vertical neighbors by one.
%C A195002 Row 6 of A194998.
%H A195002 R. H. Hardin, <a href="/A195002/b195002.txt">Table of n, a(n) for n = 1..200</a>
%F A195002 Empirical: a(n) = 61488*n - 169100 for n>8.
%F A195002 Empirical g.f.: 2*x*(1 + 2302*x + 10914*x^2 + 11769*x^3 + 3985*x^4 + 1545*x^5 + 152*x^6 + 73*x^7 + 2*x^8 + x^9) / (1 - x)^2. - _Colin Barker_, May 06 2018
%e A195002 Some solutions for n=4:
%e A195002 ..4............2............2............4............2............0
%e A195002 ..3.4..........3.2..........1.0..........3.4..........3.4..........1.2
%e A195002 ..2.3.2........4.3.2........0.1.0........2.3.4........4.3.2........2.3.4
%e A195002 ..1.2.3.2......3.2.3.4......1.2.1.2......3.4.3.4......3.4.3.2......1.2.3.2
%e A195002 ..0.1.2.3.2....2.3.4.3.2....0.1.0.1.2....2.3.2.3.2....2.3.2.1.2....2.1.2.1.2
%e A195002 ..1.2.1.2.1.0..3.4.3.4.3.2..1.2.1.2.1.2..3.2.3.2.3.2..3.2.3.2.1.0..3.2.3.2.1.2
%Y A195002 Cf. A194998.
%K A195002 nonn
%O A195002 1,1
%A A195002 _R. H. Hardin_, Sep 07 2011