[go: up one dir, main page]

login
Number of lower triangles of a 7X7 0..n array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by two or less
1

%I #5 Mar 31 2012 12:36:24

%S 268435456,22876792454961,254948725307650,786909681200387,

%T 1479091549959182,2226347741716207,2987571816007840,3751562406061261,

%U 4515974674903982,5280435818615649,6044900876514412,6809366105107111

%N Number of lower triangles of a 7X7 0..n array with each element differing from all of its diagonal, vertical, antidiagonal and horizontal neighbors by two or less

%C Row 7 of A195248

%H R. H. Hardin, <a href="/A195253/b195253.txt">Table of n, a(n) for n = 1..200</a>

%F Empirical: a(n) = 764465228592699*n - 2364216638005277 for n>10

%e Some solutions for n=5

%e ..3..............2..............5..............0..............5

%e ..4.5............3.4............4.3............2.0............3.3

%e ..4.4.3..........5.4.5..........2.4.4..........0.2.0..........2.2.4

%e ..2.3.2.4........5.5.4.4........3.3.2.4........2.2.2.0........1.2.3.2

%e ..3.3.3.3.4......3.4.4.2.3......3.4.3.4.3......2.1.0.1.1......0.2.4.4.2

%e ..3.3.1.2.4.4....2.4.3.2.2.1....3.4.5.3.2.2....0.1.2.1.1.2....0.2.3.3.4.4

%e ..3.2.2.3.4.5.4..2.2.2.2.3.1.1..3.3.3.3.2.1.1..1.2.3.2.0.1.0..2.2.1.3.3.5.3

%K nonn

%O 1,1

%A _R. H. Hardin_ Sep 13 2011