A189884 - OEIS

%I #8 Mar 11 2024 13:33:01

%S 0,0,0,32,96,192,320,560,912,1368,1920,2712,3728,4960,6400,8256,10480,

%T 13064,16000,19600,23736,28408,33608,39768,46680,54344,62744,72448,

%U 83152,94864,107568,121968,137648,154624,172880,193296,215304,238920,264136

%N Number of 1:4:sqrt(17) proportioned triangles on a (n+1) X (n+1) grid.

%H R. H. Hardin, <a href="/A189884/b189884.txt">Table of n, a(n) for n = 1..115</a>

%F Empirical: a(n) = a(n-1) +2*a(n-4) -2*a(n-5) -a(n-8) +a(n-9) +a(n-16) -a(n-18) -2*a(n-20) +2*a(n-22) +a(n-24) -a(n-26) -a(n-33) +a(n-34) +2*a(n-37) -2*a(n-38) -a(n-41) +a(n-42)

%e Some solutions for n=4

%e ..2..0....4..0....2..4....1..0....0..0....1..4....4..4....0..4....4..3....3..4

%e ..1..0....3..0....1..4....0..0....0..1....1..0....0..4....0..0....0..3....2..4

%e ..2..4....4..4....2..0....1..4....4..0....2..4....4..3....1..4....4..2....3..0

%Y Main diagonal of A189885.

%K nonn

%O 1,4

%A _R. H. Hardin_, Apr 29 2011