%I #8 Mar 11 2024 13:35:24
%S 0,0,24,80,168,344,624,1008,1584,2368,3360,4704,6384,8408,10984,14064,
%T 17664,22056,27152,32976,39888,47736,56544,66776,78216,90888,105360,
%U 121344,138864,158616,180216,203688,229856,258248,288888,322728,359200
%N Number of 1:3:sqrt(10) proportioned triangles on a (n+1) X (n+1) grid.
%H R. H. Hardin, <a href="/A190102/b190102.txt">Table of n, a(n) for n = 1..99</a>
%F Empirical: a(n) = a(n-1) +2*a(n-3) -2*a(n-4) -a(n-6) +a(n-7) +a(n-9) -a(n-11) -2*a(n-12) +2*a(n-14) +a(n-15) -a(n-17) -a(n-19) +a(n-20) +2*a(n-22) -2*a(n-23) -a(n-25) +a(n-26)
%e Some solutions for n=5
%e ..5..3....1..2....3..0....4..5....1..1....1..4....3..1....5..3....0..2....2..4
%e ..2..0....1..5....3..3....3..5....1..4....2..5....0..4....2..3....0..1....1..4
%e ..4..4....2..2....4..0....4..2....2..1....4..1....2..0....5..2....3..2....2..1
%Y Main diagonal of A190103.
%K nonn
%O 1,3
%A _R. H. Hardin_, May 04 2011