|
|
A259220
|
|
Number of (n+1) X (6+1) 0..1 arrays with each 2 X 2 subblock having clockwise pattern 0000 0011 or 0101.
|
|
2
|
|
|
162, 230, 334, 510, 798, 1278, 2078, 3422, 5694, 9566, 16222, 27774, 48030, 83934, 148286, 264926, 478686, 874622, 1615390, 3014238, 5678142, 10789470, 20661854, 39839870, 77278878, 150673118, 295060798, 579951582, 1143447774, 2260270206
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
1,1
|
|
LINKS
|
|
|
FORMULA
|
a(n) = 4*a(n-1) - 4*a(n-2) - a(n-3) + 2*a(n-4).
G.f.: 2*x*(81 - 209*x + 31*x^2 + 128*x^3) / ((1 - x)*(1 - 2*x)*(1 - x - x^2)). - Colin Barker, Dec 24 2018
From the above formulae, a(n) = 2*(2^n + 16*Fibonacci(n+3) + 31). - Ehren Metcalfe, Dec 27 2018
|
|
EXAMPLE
|
Some solutions for n=4:
0 1 0 1 0 1 0 0 1 1 1 0 1 1 1 1 0 0 1 1 1
0 1 0 1 0 1 0 1 0 0 0 1 0 0 0 0 1 1 0 0 0
0 1 0 1 0 1 0 1 0 0 0 1 0 0 1 1 0 0 1 1 1
0 1 0 1 0 1 0 0 1 1 1 0 1 1 0 0 1 1 0 0 0
1 0 1 0 1 0 1 1 0 0 0 1 0 0 1 1 0 0 1 1 1
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|