cp's OEIS Frontend

A195001 Number of lower triangles of a 5 X 5 0..n array with each element differing from all of its horizontal and vertical neighbors by one.

%I A195001 #9 May 06 2018 10:12:37
%S A195001 2,576,2290,4990,7858,10804,13754,16706,19658,22610,25562,28514,31466,
%T A195001 34418,37370,40322,43274,46226,49178,52130,55082,58034,60986,63938,
%U A195001 66890,69842,72794,75746,78698,81650,84602,87554,90506,93458,96410,99362
%N A195001 Number of lower triangles of a 5 X 5 0..n array with each element differing from all of its horizontal and vertical neighbors by one.
%C A195001 Row 5 of A194998.
%H A195001 R. H. Hardin, <a href="/A195001/b195001.txt">Table of n, a(n) for n = 1..200</a>
%F A195001 Empirical: a(n) = 2952*n - 6910 for n>6.
%F A195001 Empirical g.f.: 2*x*(1 + 286*x + 570*x^2 + 493*x^3 + 84*x^4 + 39*x^5 + 2*x^6 + x^7) / (1 - x)^2. - _Colin Barker_, May 06 2018
%e A195001 Some solutions for n=4:
%e A195001 ..0..........0..........1..........0..........0..........4..........1
%e A195001 ..1.2........1.2........2.1........1.2........1.0........3.2........2.1
%e A195001 ..2.1.0......2.1.2......1.2.3......2.1.2......2.1.0......2.3.2......1.2.3
%e A195001 ..1.2.1.2....1.2.1.2....0.1.2.3....3.2.3.4....3.2.1.2....3.4.3.2....0.1.2.3
%e A195001 ..0.1.2.3.4..2.1.0.1.0..1.2.3.2.3..2.3.2.3.2..2.3.2.1.0..4.3.2.1.0..1.2.3.4.3
%Y A195001 Cf. A194998.
%K A195001 nonn
%O A195001 1,1
%A A195001 _R. H. Hardin_, Sep 07 2011